InPrePaint document state and PrePaintTreeWalk class

third_party/WebKit/Source/core/paint/PrePaintTreeWalk.cpp

+// Copyright 2015 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 "core/paint/PrePaintTreeWalk.h"
+
+#include "core/dom/DocumentLifecycle.h"
+#include "core/frame/FrameView.h"
+#include "core/frame/LocalFrame.h"
+#include "core/layout/LayoutPart.h"
+#include "core/layout/LayoutView.h"
+
+namespace blink {
+
+struct PrePaintTreeWalkContext {
+    PaintPropertyTreeBuilderContext treeBuilderContext;
+};
+
+void PrePaintTreeWalk::walk(FrameView& rootFrame)
+{
+    DCHECK(rootFrame.frame().document()->lifecycle().state() == DocumentLifecycle::InPrePaint);
+
+    PaintPropertyTreeBuilderRootContext treeBuilderRootContext;
+    m_propertyTreeBuilder.buildTreeRootNodes(rootFrame, treeBuilderRootContext);
+    PrePaintTreeWalkContext rootContext = { treeBuilderRootContext };
+    walk(rootFrame, rootContext);
+}
+
+void PrePaintTreeWalk::walk(FrameView& frameView, const PrePaintTreeWalkContext& context)
+{
+    PrePaintTreeWalkContext localContext(context);
+    m_propertyTreeBuilder.buildTreeNodes(frameView, localContext.treeBuilderContext);
+    if (LayoutView* layoutView = frameView.layoutView())
+        walk(*layoutView, localContext);
+}
+
+void PrePaintTreeWalk::walk(const LayoutObject& object, const PrePaintTreeWalkContext& context)
+{
+    PrePaintTreeWalkContext localContext(context);
+    m_propertyTreeBuilder.buildTreeNodes(object, localContext.treeBuilderContext);
+
+    for (const LayoutObject* child = object.slowFirstChild(); child; child = child->nextSibling()) {
+        if (child->isBoxModelObject() || child->isSVG())
+            walk(*child, localContext);
+    }
+
+    if (object.isLayoutPart()) {
+        Widget* widget = toLayoutPart(object).widget();
+        if (widget && widget->isFrameView())
+            walk(*toFrameView(widget), localContext);
+        // TODO(pdr): Investigate RemoteFrameView (crbug.com/579281).
+    }
+}
+
+} // namespace blink