Combine PaintPropertyTreeBuilderRootContext into PaintPropertyTreeBuilder

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 };
+    PrePaintTreeWalkContext rootContext;
+    m_propertyTreeBuilder.buildTreeRootNodes(rootFrame, rootContext.treeBuilderContext);
     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);
 }
@@ skipping 10 matching lines @@
 
     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