3 files changed, 866 insertions, 0 deletions
diff --git a/Source/WebCore/Scripts/DumpEditingHistory.js b/Source/WebCore/Scripts/DumpEditingHistory.js
new file mode 100644
index 000000000..16b1d81b2
--- /dev/null
+++ b/Source/WebCore/Scripts/DumpEditingHistory.js
@@ -0,0 +1,82 @@
+(() => {
+    let initialized = false;
+    let globalNodeMap = new EditingHistory.GlobalNodeMap();
+    let topLevelUpdates = [];
+    let currentChildUpdates = [];
+    let isProcessingTopLevelUpdate = false;
+    let lastKnownSelectionState = null;
+    let mutationObserver = new MutationObserver(records => appendDOMUpdatesFromRecords(records));
+
+    function beginProcessingTopLevelUpdate() {
+        isProcessingTopLevelUpdate = true;
+    }
+
+    function endProcessingTopLevelUpdate(topLevelUpdate) {
+        topLevelUpdates.push(topLevelUpdate);
+        currentChildUpdates = [];
+        isProcessingTopLevelUpdate = false;
+    }
+
+    function appendDOMUpdatesFromRecords(records) {
+        if (!records.length)
+            return;
+
+        let newUpdates = EditingHistory.DOMUpdate.fromRecords(records, globalNodeMap);
+        if (isProcessingTopLevelUpdate)
+            currentChildUpdates = currentChildUpdates.concat(newUpdates);
+        else
+            topLevelUpdates = topLevelUpdates.concat(newUpdates);
+    }
+
+    function appendSelectionUpdateIfNecessary() {
+        let newSelectionState = EditingHistory.SelectionState.fromSelection(getSelection(), globalNodeMap);
+        if (newSelectionState.isEqual(lastKnownSelectionState))
+            return;
+
+        let update = new EditingHistory.SelectionUpdate(globalNodeMap, newSelectionState);
+        if (isProcessingTopLevelUpdate)
+            currentChildUpdates.push(update);
+        else
+            topLevelUpdates.push(update);
+        lastKnownSelectionState = newSelectionState;
+    }
+
+    document.body.addEventListener("focus", () => {
+        if (initialized)
+            return;
+
+        initialized = true;
+
+        EditingHistory.getEditingHistoryAsJSONString = (formatted) => {
+            let record = {};
+            record.updates = topLevelUpdates.map(update => update.toObject());
+            record.globalNodeMap = globalNodeMap.toObject();
+            return formatted ? JSON.stringify(record, null, 4) : JSON.stringify(record);
+        };
+
+        document.addEventListener("selectionchange", () => {
+            appendSelectionUpdateIfNecessary();
+        });
+
+        document.addEventListener("beforeinput", event => {
+            appendDOMUpdatesFromRecords(mutationObserver.takeRecords());
+            beginProcessingTopLevelUpdate();
+        });
+
+        document.addEventListener("input", event => {
+            appendDOMUpdatesFromRecords(mutationObserver.takeRecords());
+            let eventData = event.dataTransfer ? event.dataTransfer.getData("text/html") : event.data;
+            lastKnownSelectionState = null;
+            endProcessingTopLevelUpdate(new EditingHistory.InputEventUpdate(globalNodeMap, currentChildUpdates, event.inputType, eventData, event.timeStamp));
+        });
+
+        mutationObserver.observe(document, {
+            childList: true,
+            attributes: true,
+            characterData: true,
+            subtree: true,
+            attributeOldValue: true,
+            characterDataOldValue: true,
+        });
+    });
+})();
diff --git a/Source/WebCore/Scripts/EditingHistoryUtil.js b/Source/WebCore/Scripts/EditingHistoryUtil.js
new file mode 100644
index 000000000..645870b3d
--- /dev/null
+++ b/Source/WebCore/Scripts/EditingHistoryUtil.js
@@ -0,0 +1,693 @@
+(() => {
+    class Obfuscator {
+        constructor() {
+            this._scrambledLowercaseLetters = this._scramble(Array(26).fill().map((_, i) => 97 + i));
+            this._scrambledUppercaseLetters = this._scramble(Array(26).fill().map((_, i) => 65 + i));
+            this._scrambledNumbers = this._scramble(Array(10).fill().map((_, i) => 48 + i));
+            this.enabled = false;
+        }
+
+        _scramble(array) {
+            for (var i = array.length - 1; i > 0; i--) {
+                let j = Math.floor(Math.random() * (i + 1));
+                let temp = array[i];
+                array[i] = array[j];
+                array[j] = temp;
+            }
+            return array;
+        }
+
+        applyToText(text) {
+            if (!this.enabled || !text)
+                return text;
+
+            let result = "";
+            for (let index = 0; index < text.length; index++) {
+                let code = text.charCodeAt(index);
+                let numberIndex = this._scrambedNumberIndexForCode(code);
+                let lowercaseIndex = this._scrambedLowercaseIndexForCode(code);
+                let uppercaseIndex = this._scrambedUppercaseIndexForCode(code);
+
+                if (numberIndex != null)
+                    result += String.fromCharCode(this._scrambledNumbers[numberIndex]);
+                else if (lowercaseIndex != null)
+                    result += String.fromCharCode(this._scrambledLowercaseLetters[lowercaseIndex]);
+                else if (uppercaseIndex != null)
+                    result += String.fromCharCode(this._scrambledUppercaseLetters[uppercaseIndex]);
+                else
+                    result += text.charAt(index);
+            }
+            return result;
+        }
+
+        applyToFilename(filename) {
+            if (!this.enabled || !filename)
+                return filename;
+
+            let components = filename.split(".");
+            return components.map((component, index) => {
+                if (index == components.length - 1)
+                    return component;
+
+                return this.applyToText(component);
+            }).join(".");
+        }
+
+        _scrambedNumberIndexForCode(code) {
+            return 48 <= code && code <= 57 ? code - 48 : null;
+        }
+
+        _scrambedLowercaseIndexForCode(code) {
+            return 97 <= code && code <= 122 ? code - 97 : null;
+        }
+
+        _scrambedUppercaseIndexForCode(code) {
+            return 65 <= code && code <= 90 ? code - 65 : null;
+        }
+
+        static shared() {
+            if (!Obfuscator._sharedInstance)
+                Obfuscator._sharedInstance = new Obfuscator();
+            return Obfuscator._sharedInstance;
+        }
+    }
+
+    function elementFromMarkdown(html) {
+        let temporaryDiv = document.createElement("div");
+        temporaryDiv.innerHTML = html;
+        return temporaryDiv.children[0];
+    }
+
+    class GlobalNodeMap {
+        constructor(nodesByGUID) {
+            this._nodesByGUID = nodesByGUID ? nodesByGUID : new Map();
+            this._guidsByNode = new Map();
+            this._currentGUID = 0;
+            for (let [guid, node] of this._nodesByGUID) {
+                this._guidsByNode.set(node, guid);
+                this._currentGUID = Math.max(this._currentGUID, guid);
+            }
+            this._currentGUID++;
+        }
+
+        nodesForGUIDs(guids) {
+            if (!guids.map)
+                guids = Array.from(guids);
+            return guids.map(guid => this.nodeForGUID(guid));
+        }
+
+        guidsForNodes(nodes) {
+            if (!nodes.map)
+                nodes = Array.from(nodes);
+            return nodes.map(node => this.guidForNode(node));
+        }
+
+        nodeForGUID(guid) {
+            if (!guid)
+                return null;
+
+            return this._nodesByGUID.get(guid);
+        }
+
+        guidForNode(node) {
+            if (!node)
+                return 0;
+
+            if (this.hasGUIDForNode(node))
+                return this._guidsByNode.get(node);
+
+            const guid = this._currentGUID;
+            this._guidsByNode.set(node, guid);
+            this._nodesByGUID.set(guid, node);
+            this._currentGUID++;
+            return guid;
+        }
+
+        hasGUIDForNode(node) {
+            return !!this._guidsByNode.get(node);
+        }
+
+        nodes() {
+            return Array.from(this._nodesByGUID.values());
+        }
+
+        toObject() {
+            let nodesAndGUIDsToProcess = [], guidsToProcess = new Set();
+            let guidsByNodeIterator = this._guidsByNode.entries();
+            for (let entry = guidsByNodeIterator.next(); !entry.done; entry = guidsByNodeIterator.next()) {
+                nodesAndGUIDsToProcess.push(entry.value);
+                guidsToProcess.add(entry.value[1]);
+            }
+
+            let iterator = document.createNodeIterator(document.body, NodeFilter.SHOW_ALL);
+            for (let node = iterator.nextNode(); node; node = iterator.nextNode()) {
+                if (this.hasGUIDForNode(node))
+                    continue;
+
+                let newGUID = this.guidForNode(node);
+                nodesAndGUIDsToProcess.push([node, newGUID]);
+                guidsToProcess.add(newGUID);
+            }
+
+            let nodeInfoArray = [];
+            while (nodesAndGUIDsToProcess.length) {
+                let [node, guid] = nodesAndGUIDsToProcess.pop();
+                let info = {};
+                info.guid = guid;
+                info.tagName = node.tagName;
+                info.attributes = GlobalNodeMap.nodeAttributesToObject(node);
+                info.type = node.nodeType;
+                info.data = GlobalNodeMap.dataForNode(node);
+                if (node.hasChildNodes()) {
+                    info.childGUIDs = this.guidsForNodes(node.childNodes);
+                    for (let childGUID of info.childGUIDs) {
+                        if (!guidsToProcess.has(childGUID))
+                            nodesAndGUIDsToProcess.push([this.nodeForGUID(childGUID), childGUID]);
+                    }
+                }
+                nodeInfoArray.push(info);
+            }
+
+            return nodeInfoArray;
+        }
+
+        static fromObject(nodeInfoArray) {
+            let nodesByGUID = new Map();
+            for (let info of nodeInfoArray) {
+                let node = null;
+                if (info.type == Node.ELEMENT_NODE)
+                    node = GlobalNodeMap.elementFromTagName(info.tagName, info.attributes, info.data);
+
+                if (info.type == Node.TEXT_NODE)
+                    node = document.createTextNode(info.data);
+
+                if (info.type == Node.DOCUMENT_NODE)
+                    node = document;
+
+                console.assert(node);
+                nodesByGUID.set(info.guid, node);
+            }
+
+            // Then, set child nodes for all nodes that do not appear in the DOM.
+            for (let info of nodeInfoArray.filter(info => !!info.childGUIDs)) {
+                let node = nodesByGUID.get(info.guid);
+                for (let childGUID of info.childGUIDs)
+                     node.appendChild(nodesByGUID.get(childGUID));
+            }
+
+            return new GlobalNodeMap(nodesByGUID);
+        }
+
+        static dataForNode(node) {
+            if (node.nodeType === Node.TEXT_NODE)
+                return Obfuscator.shared().applyToText(node.data);
+
+            if (node.tagName && node.tagName.toLowerCase() === "attachment") {
+                return {
+                    type: node.file.type,
+                    name: Obfuscator.shared().applyToFilename(node.file.name),
+                    lastModified: new Date().getTime()
+                };
+            }
+
+            return null;
+        }
+
+        static elementFromTagName(tagName, attributes, data) {
+            let node = document.createElement(tagName);
+            for (let attributeName in attributes)
+                node.setAttribute(attributeName, attributes[attributeName]);
+
+            if (tagName.toLowerCase() == "attachment") {
+                node.file = new File([`File named '${data.name}'`], data.name, {
+                    type: data.type,
+                    lastModified: data.lastModified
+                });
+            }
+
+            return node;
+        }
+
+        // Returns an Object containing attribute name => attribute value
+        static nodeAttributesToObject(node, attributesToExclude=[]) {
+            const excludeAttributesSet = new Set(attributesToExclude);
+            if (!node.attributes)
+                return null;
+
+            let attributeMap = {};
+            for (let index = 0; index < node.attributes.length; index++) {
+                const attribute = node.attributes.item(index);
+                const [localName, value] = [attribute.localName, attribute.value];
+                if (excludeAttributesSet.has(localName))
+                    continue;
+
+                attributeMap[localName] = value;
+            }
+
+            return attributeMap;
+        }
+
+        descriptionHTMLForGUID(guid) {
+            return `<span eh-guid=${guid} class="eh-node">${this.nodeForGUID(guid).nodeName}</span>`;
+        }
+
+        descriptionHTMLForNode(node) {
+            if (!node)
+                return "(null)";
+            return `<span eh-guid=${this.guidForNode(node)} class="eh-node">${node.nodeName}</span>`;
+        }
+    }
+
+    class SelectionState {
+        constructor(nodeMap, startNode, startOffset, endNode, endOffset, anchorNode, anchorOffset, focusNode, focusOffset) {
+            console.assert(nodeMap);
+            this.nodeMap = nodeMap;
+            this.startGUID = nodeMap.guidForNode(startNode);
+            this.startOffset = startOffset;
+            this.endGUID = nodeMap.guidForNode(endNode);
+            this.endOffset = endOffset;
+            this.anchorGUID = nodeMap.guidForNode(anchorNode);
+            this.anchorOffset = anchorOffset;
+            this.focusGUID = nodeMap.guidForNode(focusNode);
+            this.focusOffset = focusOffset;
+        }
+
+        isEqual(otherSelectionState) {
+            return otherSelectionState
+                && this.startGUID === otherSelectionState.startGUID && this.startOffset === otherSelectionState.startOffset
+                && this.endGUID === otherSelectionState.endGUID && this.endOffset === otherSelectionState.endOffset
+                && this.anchorGUID === otherSelectionState.anchorGUID && this.anchorOffset === otherSelectionState.anchorOffset
+                && this.focusGUID === otherSelectionState.focusGUID && this.focusOffset === otherSelectionState.focusOffset;
+        }
+
+        applyToSelection(selection) {
+            selection.removeAllRanges();
+            let range = document.createRange();
+            range.setStart(this.nodeMap.nodeForGUID(this.startGUID), this.startOffset);
+            range.setEnd(this.nodeMap.nodeForGUID(this.endGUID), this.endOffset);
+            selection.addRange(range);
+            selection.setBaseAndExtent(this.nodeMap.nodeForGUID(this.anchorGUID), this.anchorOffset, this.nodeMap.nodeForGUID(this.focusGUID), this.focusOffset);
+        }
+
+        static fromSelection(selection, nodeMap) {
+            let [startNode, startOffset, endNode, endOffset] = [null, 0, null, 0];
+            if (selection.rangeCount) {
+                let selectedRange = selection.getRangeAt(0);
+                startNode = selectedRange.startContainer;
+                startOffset = selectedRange.startOffset;
+                endNode = selectedRange.endContainer;
+                endOffset = selectedRange.endOffset;
+            }
+            return new SelectionState(
+                nodeMap, startNode, startOffset, endNode, endOffset,
+                selection.anchorNode, selection.anchorOffset, selection.focusNode, selection.focusOffset
+            );
+        }
+
+        toObject() {
+            return {
+                startGUID: this.startGUID, startOffset: this.startOffset, endGUID: this.endGUID, endOffset: this.endOffset,
+                anchorGUID: this.anchorGUID, anchorOffset: this.anchorOffset, focusGUID: this.focusGUID, focusOffset: this.focusOffset
+            };
+        }
+
+        static fromObject(json, nodeMap) {
+            if (!json)
+                return null;
+
+            return new SelectionState(
+                nodeMap, nodeMap.nodeForGUID(json.startGUID), json.startOffset, nodeMap.nodeForGUID(json.endGUID), json.endOffset,
+                nodeMap.nodeForGUID(json.anchorGUID), json.anchorOffset, nodeMap.nodeForGUID(json.focusGUID), json.focusOffset
+            );
+        }
+    }
+
+    class DOMUpdate {
+        constructor(nodeMap) {
+            console.assert(nodeMap);
+            this.nodeMap = nodeMap;
+        }
+
+        apply() {
+            throw "Expected subclass implementation.";
+        }
+
+        unapply() {
+            throw "Expected subclass implementation.";
+        }
+
+        targetNode() {
+            return this.nodeMap.nodeForGUID(this.targetGUID);
+        }
+
+        detailsElement() {
+            throw "Expected subclass implementation.";
+        }
+
+        static ofType(type) {
+            if (!DOMUpdate._allTypes)
+                DOMUpdate._allTypes = { ChildListUpdate, CharacterDataUpdate, AttributeUpdate, InputEventUpdate, SelectionUpdate };
+            return DOMUpdate._allTypes[type];
+        }
+
+        static fromRecords(records, nodeMap) {
+            let updates = []
+                , characterDataUpdates = []
+                , attributeUpdates = [];
+
+            for (let record of records) {
+                let target = record.target;
+                switch (record.type) {
+                case "characterData":
+                    var update = new CharacterDataUpdate(nodeMap, nodeMap.guidForNode(target), record.oldValue, target.data)
+                    updates.push(update);
+                    characterDataUpdates.push(update);
+                    break;
+                case "childList":
+                    var update = new ChildListUpdate(nodeMap, nodeMap.guidForNode(target), nodeMap.guidsForNodes(record.addedNodes), nodeMap.guidsForNodes(record.removedNodes), nodeMap.guidForNode(record.nextSibling))
+                    updates.push(update);
+                    break;
+                case "attributes":
+                    var update = new AttributeUpdate(nodeMap, nodeMap.guidForNode(target), record.attributeName, record.oldValue, target.getAttribute(record.attributeName))
+                    updates.push(update);
+                    attributeUpdates.push(update);
+                    break;
+                }
+            }
+
+            // Adjust all character data updates for the same target.
+            characterDataUpdates.forEach((currentUpdate, index) => {
+                if (index == characterDataUpdates.length - 1)
+                    return;
+
+                for (let nextUpdateIndex = index + 1; nextUpdateIndex < characterDataUpdates.length; nextUpdateIndex++) {
+                    let nextUpdate = characterDataUpdates[nextUpdateIndex];
+                    if (currentUpdate.targetGUID === nextUpdate.targetGUID) {
+                        currentUpdate.newData = nextUpdate.oldData;
+                        break;
+                    }
+                }
+            });
+
+            // Adjust all attribute updates for the same target and attribute name.
+            attributeUpdates.forEach((currentUpdate, index) => {
+                if (index == attributeUpdates.length - 1)
+                    return;
+
+                for (let nextUpdateIndex = index + 1; nextUpdateIndex < attributeUpdates.length; nextUpdateIndex++) {
+                    let nextUpdate = attributeUpdates[nextUpdateIndex];
+                    if (currentUpdate.targetGUID === nextUpdate.targetGUID && currentUpdate.attribute === nextUpdate.attribute) {
+                        currentUpdate.newData = nextUpdate.oldData;
+                        break;
+                    }
+                }
+            });
+
+            return updates;
+        }
+    }
+
+    class ChildListUpdate extends DOMUpdate {
+        constructor(nodeMap, targetGUID, addedGUIDs, removedGUIDs, nextSiblingGUID) {
+            super(nodeMap);
+            this.targetGUID = targetGUID;
+            this.added = addedGUIDs;
+            this.removed = removedGUIDs;
+            this.nextSiblingGUID = nextSiblingGUID == undefined ? null : nextSiblingGUID;
+            console.assert(nodeMap.nodeForGUID(targetGUID));
+        }
+
+        apply() {
+            for (let removedNode of this._removedNodes())
+                removedNode.remove();
+
+            let target = this.targetNode();
+            for (let addedNode of this._addedNodes())
+                target.insertBefore(addedNode, this._nextSibling());
+        }
+
+        unapply() {
+            for (let addedNode of this._addedNodes())
+                addedNode.remove();
+
+            let target = this.targetNode();
+            for (let removedNode of this._removedNodes())
+                target.insertBefore(removedNode, this._nextSibling());
+        }
+
+        _nextSibling() {
+            if (this.nextSiblingGUID == null)
+                return null;
+            return this.nodeMap.nodeForGUID(this.nextSiblingGUID);
+        }
+
+        _removedNodes() {
+            return this.nodeMap.nodesForGUIDs(this.removed);
+        }
+
+        _addedNodes() {
+            return this.nodeMap.nodesForGUIDs(this.added);
+        }
+
+        toObject() {
+            return {
+                type: "ChildListUpdate",
+                targetGUID: this.targetGUID,
+                addedGUIDs: this.added,
+                removedGUIDs: this.removed,
+                nextSiblingGUID: this.nextSiblingGUID
+            };
+        }
+
+        detailsElement() {
+            let nextSibling = this._nextSibling();
+            let html =
+            `<details>
+                <summary>child list changed</summary>
+                <ul>
+                    <li>parent: ${this.nodeMap.descriptionHTMLForGUID(this.targetGUID)}</li>
+                    <li>added: [ ${[this._addedNodes().map(node => this.nodeMap.descriptionHTMLForNode(node))]} ]</li>
+                    <li>removed: [ ${[this._removedNodes().map(node => this.nodeMap.descriptionHTMLForNode(node))]} ]</li>
+                    <li>before sibling: ${nextSibling ? this.nodeMap.descriptionHTMLForNode(nextSibling) : "(null)"}</li>
+                </ul>
+            </details>`;
+            return elementFromMarkdown(html);
+        }
+
+        static fromObject(json, nodeMap) {
+            return new ChildListUpdate(nodeMap, json.targetGUID, json.addedGUIDs, json.removedGUIDs, json.nextSiblingGUID);
+        }
+    }
+
+    class CharacterDataUpdate extends DOMUpdate {
+        constructor(nodeMap, targetGUID, oldData, newData) {
+            super(nodeMap);
+            this.targetGUID = targetGUID;
+            this.oldData = oldData;
+            this.newData = newData;
+            console.assert(nodeMap.nodeForGUID(targetGUID));
+        }
+
+        apply() {
+            this.targetNode().data = this.newData;
+        }
+
+        unapply() {
+            this.targetNode().data = this.oldData;
+        }
+
+        detailsElement() {
+            let html =
+            `<details>
+                <summary>character data changed</summary>
+                <ul>
+                    <li>old: ${this.oldData != null ? "'" + this.oldData + "'" : "(null)"}</li>
+                    <li>new: ${this.newData != null ? "'" + this.newData + "'" : "(null)"}</li>
+                </ul>
+            </details>`;
+            return elementFromMarkdown(html);
+        }
+
+        toObject() {
+            return {
+                type: "CharacterDataUpdate",
+                targetGUID: this.targetGUID,
+                oldData: Obfuscator.shared().applyToText(this.oldData),
+                newData: Obfuscator.shared().applyToText(this.newData)
+            };
+        }
+
+        static fromObject(json, nodeMap) {
+            return new CharacterDataUpdate(nodeMap, json.targetGUID, json.oldData, json.newData);
+        }
+    }
+
+    class AttributeUpdate extends DOMUpdate {
+        constructor(nodeMap, targetGUID, attribute, oldValue, newValue) {
+            super(nodeMap);
+            this.targetGUID = targetGUID;
+            this.attribute = attribute;
+            this.oldValue = oldValue;
+            this.newValue = newValue;
+            console.assert(nodeMap.nodeForGUID(targetGUID));
+        }
+
+        apply() {
+            if (this.newValue == null)
+                this.targetNode().removeAttribute(this.attribute);
+            else
+                this.targetNode().setAttribute(this.attribute, this.newValue);
+        }
+
+        unapply() {
+            if (this.oldValue == null)
+                this.targetNode().removeAttribute(this.attribute);
+            else
+                this.targetNode().setAttribute(this.attribute, this.oldValue);
+        }
+
+        detailsElement() {
+            let html =
+            `<details>
+                <summary>attribute changed</summary>
+                <ul>
+                    <li>target: ${this.nodeMap.descriptionHTMLForGUID(this.targetGUID)}</li>
+                    <li>attribute: ${this.attribute}</li>
+                    <li>old: ${this.oldValue != null ? "'" + this.oldValue + "'" : "(null)"}</li>
+                    <li>new: ${this.newValue != null ? "'" + this.newValue + "'" : "(null)"}</li>
+                </ul>
+            </details>`;
+            return elementFromMarkdown(html);
+        }
+
+        toObject() {
+            return {
+                type: "AttributeUpdate",
+                targetGUID: this.targetGUID,
+                attribute: this.attribute,
+                oldValue: this.oldValue,
+                newValue: this.newValue
+            };
+        }
+
+        static fromObject(json, nodeMap) {
+            return new AttributeUpdate(nodeMap, json.targetGUID, json.attribute, json.oldValue, json.newValue);
+        }
+    }
+
+    class SelectionUpdate extends DOMUpdate {
+        constructor(nodeMap, state) {
+            super(nodeMap);
+            this.state = state;
+        }
+
+        // SelectionUpdates are not applied/unapplied by the normal means. The selection is applied via
+        // DOMUpdateHistoryContext.applyCurrentSelectionState instead, which considers the updates before and after the
+        // current update index.
+        apply() { }
+        unapply() { }
+
+        toObject() {
+            return {
+                type: "SelectionUpdate",
+                state: this.state ? this.state.toObject() : null
+            };
+        }
+
+        static fromObject(json, nodeMap) {
+            return new SelectionUpdate(nodeMap, SelectionState.fromObject(json.state, nodeMap));
+        }
+
+        _rangeDescriptionHTML() {
+            return `(${this.nodeMap.descriptionHTMLForGUID(this.state.startGUID)}:${this.state.startOffset},
+                ${this.nodeMap.descriptionHTMLForGUID(this.state.endGUID)}:${this.state.endOffset})`;
+        }
+
+        _anchorDescriptionHTML() {
+            return `${this.nodeMap.descriptionHTMLForGUID(this.state.anchorGUID)}:${this.state.anchorOffset}`;
+        }
+
+        _focusDescriptionHTML() {
+            return `${this.nodeMap.descriptionHTMLForGUID(this.state.focusGUID)}:${this.state.focusOffset}`;
+        }
+
+        detailsElement() {
+            let html =
+            `<details>
+                <summary>Selection changed</summary>
+                <ul>
+                    <li>range: ${this._rangeDescriptionHTML()}</li>
+                    <li>anchor: ${this._anchorDescriptionHTML()}</li>
+                    <li>focus: ${this._focusDescriptionHTML()}</li>
+                </ul>
+            </details>`;
+            return elementFromMarkdown(html);
+        }
+    }
+
+    class InputEventUpdate extends DOMUpdate {
+        constructor(nodeMap, updates, inputType, data, timeStamp) {
+            super(nodeMap);
+            this.updates = updates;
+            this.inputType = inputType;
+            this.data = data;
+            this.timeStamp = timeStamp;
+        }
+
+        _obfuscatedData() {
+            return this.inputType.indexOf("insert") == 0 ? Obfuscator.shared().applyToText(this.data) : this.data;
+        }
+
+        apply() {
+            for (let update of this.updates)
+                update.apply();
+        }
+
+        unapply() {
+            for (let index = this.updates.length - 1; index >= 0; index--)
+                this.updates[index].unapply();
+        }
+
+        toObject() {
+            return {
+                type: "InputEventUpdate",
+                inputType: this.inputType,
+                data: this._obfuscatedData(),
+                timeStamp: this.timeStamp,
+                updates: this.updates.map(update => update.toObject())
+            };
+        }
+
+        static fromObject(json, nodeMap) {
+            let updates = json.updates.map(update => DOMUpdate.ofType(update.type).fromObject(update, nodeMap));
+            return new InputEventUpdate(nodeMap, updates, json.inputType, json.data, json.timeStamp);
+        }
+
+        detailsElement() {
+            let html =
+            `<details>
+                <summary>Input (${this.inputType})</summary>
+                <ul>
+                    <li>time: ${this.timeStamp}</li>
+                    <li>data: ${!this.data ? "(null)" : "'" + this.data + "'"}</li>
+                </ul>
+            </details>`;
+            let topLevelDetails = elementFromMarkdown(html);
+            for (let update of this.updates)
+                topLevelDetails.children[topLevelDetails.childElementCount - 1].appendChild(update.detailsElement());
+            return topLevelDetails;
+        }
+    }
+
+    window.EditingHistory = {
+        GlobalNodeMap,
+        SelectionState,
+        DOMUpdate,
+        ChildListUpdate,
+        CharacterDataUpdate,
+        AttributeUpdate,
+        SelectionUpdate,
+        InputEventUpdate,
+        Obfuscator
+    };
+})();
diff --git a/Source/WebCore/Scripts/make-js-file-arrays.py b/Source/WebCore/Scripts/make-js-file-arrays.py
new file mode 100755
index 000000000..3116a11bb
--- /dev/null
+++ b/Source/WebCore/Scripts/make-js-file-arrays.py
@@ -0,0 +1,91 @@
+#!/usr/bin/env python
+# Copyright (C) 2014 Apple Inc. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1.  Redistributions of source code must retain the above copyright
+#     notice, this list of conditions and the following disclaimer.
+# 2.  Redistributions in binary form must reproduce the above copyright
+#     notice, this list of conditions and the following disclaimer in the
+#     documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
+# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
+# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+# ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+import io
+import os
+from optparse import OptionParser
+from StringIO import StringIO
+from jsmin import JavascriptMinify
+
+
+def stringifyCodepoint(code):
+    if code < 128:
+        return '{0:d}'.format(code)
+    else:
+        return "'\\x{0:02x}'".format(code)
+
+
+def chunk(list, chunkSize):
+    for i in xrange(0, len(list), chunkSize):
+        yield list[i:i + chunkSize]
+
+
+def main():
+    parser = OptionParser(usage="usage: %prog [--no-minify] header source [input [input...]]")
+    parser.add_option('--no-minify', action='store_true', help='Do not run the input files through jsmin')
+    (options, arguments) = parser.parse_args()
+    if len(arguments) < 3:
+        print 'Error: must provide at least 3 arguments'
+        parser.print_usage()
+        exit(-1)
+
+    headerPath = arguments[0]
+    sourcePath = arguments[1]
+    inputPaths = arguments[2:]
+
+    headerFile = open(headerPath, 'w')
+    print >> headerFile, 'namespace WebCore {'
+
+    sourceFile = open(sourcePath, 'w')
+    print >> sourceFile, '#include "{0:s}"'.format(os.path.basename(headerPath))
+    print >> sourceFile, 'namespace WebCore {'
+
+    jsm = JavascriptMinify()
+
+    for inputFileName in inputPaths:
+        inputStream = io.FileIO(inputFileName)
+        outputStream = StringIO()
+
+        if not options.no_minify:
+            jsm.minify(inputStream, outputStream)
+            characters = outputStream.getvalue()
+        else:
+            characters = inputStream.read()
+
+        size = len(characters)
+        variableName = os.path.splitext(os.path.basename(inputFileName))[0]
+
+        print >> headerFile, 'extern const char {0:s}JavaScript[{1:d}];'.format(variableName, size)
+        print >> sourceFile, 'const char {0:s}JavaScript[{1:d}] = {{'.format(variableName, size)
+
+        codepoints = map(ord, characters)
+        for codepointChunk in chunk(codepoints, 16):
+            print >> sourceFile, '    {0:s},'.format(','.join(map(stringifyCodepoint, codepointChunk)))
+
+        print >> sourceFile, '};'
+
+    print >> headerFile, '}'
+    print >> sourceFile, '}'
+
+if __name__ == '__main__':
+    main()