Optimize PaintInvalidatorContext::mapLocalRectToVisualRectInBacking()

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/LayoutMultiColumnSpannerPlaceholder.h"
 #include "core/layout/LayoutPart.h"
 #include "core/layout/LayoutView.h"
 #include "core/paint/PaintLayer.h"
 
 namespace blink {
 
 struct PrePaintTreeWalkContext {
-  PrePaintTreeWalkContext()
+  PrePaintTreeWalkContext(GeometryMapper& geometryMapper)
       : treeBuilderContext(
             WTF::wrapUnique(new PaintPropertyTreeBuilderContext)),
-        paintInvalidatorContext(*treeBuilderContext),
+        paintInvalidatorContext(*treeBuilderContext, geometryMapper),
         ancestorOverflowPaintLayer(nullptr),
         ancestorTransformedOrRootPaintLayer(nullptr) {}
   PrePaintTreeWalkContext(const PrePaintTreeWalkContext& parentContext)
       : treeBuilderContext(WTF::wrapUnique(new PaintPropertyTreeBuilderContext(
             *parentContext.treeBuilderContext))),
         paintInvalidatorContext(*treeBuilderContext,
                                 parentContext.paintInvalidatorContext),
         ancestorOverflowPaintLayer(parentContext.ancestorOverflowPaintLayer),
         ancestorTransformedOrRootPaintLayer(
             parentContext.ancestorTransformedOrRootPaintLayer) {}
 
   // PaintPropertyTreeBuilderContext is large and can lead to stack overflows
   // when recursion is deep so this context object is allocated on the heap.
   // See: https://crbug.com/698653.
   std::unique_ptr<PaintPropertyTreeBuilderContext> treeBuilderContext;
 
   PaintInvalidatorContext paintInvalidatorContext;
 
   // The ancestor in the PaintLayer tree which has overflow clip, or
   // is the root layer. Note that it is tree ancestor, not containing
   // block or stacking ancestor.
   PaintLayer* ancestorOverflowPaintLayer;
   PaintLayer* ancestorTransformedOrRootPaintLayer;
 };
 
 void PrePaintTreeWalk::walk(FrameView& rootFrame) {
   DCHECK(rootFrame.frame().document()->lifecycle().state() ==
          DocumentLifecycle::InPrePaint);
 
-  PrePaintTreeWalkContext initialContext;
+  PrePaintTreeWalkContext initialContext(m_geometryMapper);
   m_propertyTreeBuilder.setupInitialContext(*initialContext.treeBuilderContext);
   initialContext.ancestorTransformedOrRootPaintLayer =
       rootFrame.layoutView()->layer();
 
   // GeometryMapper depends on paint properties.
   if (rootFrame.needsPaintPropertyUpdate() ||
       (rootFrame.layoutView() &&
        !shouldEndWalkBefore(*rootFrame.layoutView(), initialContext)))
     m_geometryMapper.clearCache();
 
@@ skipping 219 matching lines @@
           roundedIntPoint(context.treeBuilderContext->current.paintOffset);
       walk(*toFrameView(frameViewBase), context);
     }
     // TODO(pdr): Investigate RemoteFrameView (crbug.com/579281).
   }
 
   object.getMutableForPainting().clearPaintFlags();
 }
 
 }  // namespace blink