1 files changed, 60 insertions, 0 deletions
diff --git a/chromium/third_party/blink/renderer/platform/graphics/compositor_element_id.cc b/chromium/third_party/blink/renderer/platform/graphics/compositor_element_id.cc
new file mode 100644
index 00000000000..271bf44f49c
--- /dev/null
+++ b/chromium/third_party/blink/renderer/platform/graphics/compositor_element_id.cc
@@ -0,0 +1,60 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "third_party/blink/renderer/platform/graphics/compositor_element_id.h"
+
+namespace blink {
+
+UniqueObjectId NewUniqueObjectId() {
+  static UniqueObjectId counter = 0;
+  return ++counter;
+}
+
+static CompositorElementId CreateCompositorElementId(
+    uint64_t blink_id,
+    CompositorElementIdNamespace namespace_id) {
+  DCHECK(
+      blink_id > 0 &&
+      blink_id <
+          std::numeric_limits<uint64_t>::max() /
+              static_cast<unsigned>(
+                  CompositorElementIdNamespace::kMaxRepresentableNamespaceId));
+  // Shift to make room for namespace_id enum bits.
+  cc::ElementIdType id = blink_id << kCompositorNamespaceBitCount;
+  id += static_cast<uint64_t>(namespace_id);
+  return CompositorElementId(id);
+}
+
+CompositorElementId PLATFORM_EXPORT CompositorElementIdFromUniqueObjectId(
+    UniqueObjectId id,
+    CompositorElementIdNamespace namespace_id) {
+  DCHECK(namespace_id == CompositorElementIdNamespace::kPrimary ||
+         namespace_id == CompositorElementIdNamespace::kScroll ||
+         namespace_id == CompositorElementIdNamespace::kEffectFilter ||
+         namespace_id == CompositorElementIdNamespace::kEffectMask ||
+         namespace_id == CompositorElementIdNamespace::kEffectClipPath);
+  return CreateCompositorElementId(id, namespace_id);
+}
+
+CompositorElementId PLATFORM_EXPORT
+CompositorElementIdFromDOMNodeId(DOMNodeId id) {
+  return CreateCompositorElementId(
+      id, CompositorElementIdNamespace::kUniqueObjectId);
+}
+
+CompositorElementId PLATFORM_EXPORT
+CompositorElementIdFromUniqueObjectId(UniqueObjectId id) {
+  return CreateCompositorElementId(
+      id, CompositorElementIdNamespace::kUniqueObjectId);
+}
+
+CompositorElementIdNamespace NamespaceFromCompositorElementId(
+    CompositorElementId element_id) {
+  return static_cast<CompositorElementIdNamespace>(
+      element_id.ToInternalValue() %
+      static_cast<uint64_t>(
+          CompositorElementIdNamespace::kMaxRepresentableNamespaceId));
+}
+
+}  // namespace blink