BASELINE: Update Chromium to 78.0.3904.130

Change-Id: If185e0c0061b3437531c97c9c8c78f239352a68b
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

1 files changed, 76 insertions, 0 deletions

diff --git a/chromium/third_party/blink/renderer/core/layout/ng/custom/custom_layout_scope.h b/chromium/third_party/blink/renderer/core/layout/ng/custom/custom_layout_scope.h
new file mode 100644
index 00000000000..319ea6b778b
--- /dev/null
+++ b/chromium/third_party/blink/renderer/core/layout/ng/custom/custom_layout_scope.h
@@ -0,0 +1,76 @@
+// Copyright 2019 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.
+
+#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_NG_CUSTOM_CUSTOM_LAYOUT_SCOPE_H_
+#define THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_NG_CUSTOM_CUSTOM_LAYOUT_SCOPE_H_
+
+#include "third_party/blink/renderer/core/layout/ng/custom/custom_layout_work_task.h"
+#include "third_party/blink/renderer/platform/heap/handle.h"
+
+namespace blink {
+
+// The work queue is a list of work tasks which will either produce fragment(s)
+// or intrinsic-size(s) for the custom-layout class.
+typedef Vector<CustomLayoutWorkTask, 4> CustomLayoutWorkQueue;
+
+// This heap allocated class is used to indicate which custom-layout (heap)
+// objects are still valid.
+//
+// Any objects which have a pointer to this object with |is_detached_| being
+// true, or not matching the current scope token should be considered invalid.
+class CustomLayoutToken : public GarbageCollected<CustomLayoutToken> {
+ public:
+  CustomLayoutToken() : is_detached_(false) {}
+  void Trace(Visitor* visitor) {}
+  bool IsValid() const;
+
+ private:
+  friend class CustomLayoutScope;
+  bool is_detached_;
+};
+
+// This scope object is used to track which custom-layout (heap) objects are
+// valid.
+//
+// Also maintains the current work queue. Work should only be pushed onto this
+// queue if this is the current scope.
+class CustomLayoutScope {
+  STACK_ALLOCATED();
+
+ public:
+  static CustomLayoutScope* Current() { return current_scope_; }
+
+  CustomLayoutScope()
+      : prev_scope_(current_scope_),
+        token_(MakeGarbageCollected<CustomLayoutToken>()) {
+    current_scope_ = this;
+  }
+
+  // Marks the scope-token as "detached" for any classes with a pointer to it.
+  ~CustomLayoutScope() {
+    token_->is_detached_ = true;
+    current_scope_ = current_scope_->prev_scope_;
+  }
+
+  CustomLayoutWorkQueue* Queue() {
+    DCHECK_EQ(this, current_scope_);
+    return &queue_;
+  }
+  CustomLayoutToken* Token() { return token_; }
+
+ private:
+  static CustomLayoutScope* current_scope_;
+
+  CustomLayoutScope* prev_scope_;
+  CustomLayoutWorkQueue queue_;
+  Member<CustomLayoutToken> token_;
+};
+
+inline bool CustomLayoutToken::IsValid() const {
+  return !is_detached_ && this == CustomLayoutScope::Current()->Token();
+}
+
+}  // namespace blink
+
+#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_NG_CUSTOM_CUSTOM_LAYOUT_SCOPE_H_