Support high DPI scrollbar on top level web frame.

cc/LayerChromium.h

 // Copyright 2010 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 LayerChromium_h
 #define LayerChromium_h
 
 #if USE(ACCELERATED_COMPOSITING)
 
@@ skipping 212 matching lines @@
     const WebKit::WebTransformationMatrix& screenSpaceTransform() const { return m_screenSpaceTransform; }
     void setScreenSpaceTransform(const WebKit::WebTransformationMatrix& matrix) { m_screenSpaceTransform = matrix; }
     const IntRect& drawableContentRect() const { return m_drawableContentRect; }
     void setDrawableContentRect(const IntRect& rect) { m_drawableContentRect = rect; }
     // The contentsScale converts from logical, non-page-scaled pixels to target pixels.
     // The contentsScale is 1 for the root layer as it is already in physical pixels.
     float contentsScale() const { return m_contentsScale; }
     void setContentsScale(float);
 
     // When true, the layer's contents are not scaled by the current page scale factor.
+    // setBoundsContainPageScale recursively sets the value on all child layers.
     void setBoundsContainPageScale(bool);
     bool boundsContainPageScale() const { return m_boundsContainPageScale; }
 
     // Returns true if any of the layer's descendants has content to draw.
     bool descendantDrawsContent();
 
     CCLayerTreeHost* layerTreeHost() const { return m_layerTreeHost; }
 
     // Set the priority of all desired textures in this layer.
     virtual void setTexturePriorities(const CCPriorityCalculator&) { }
@@ skipping 21 matching lines @@
     virtual ScrollbarLayerChromium* toScrollbarLayerChromium() { return 0; }
 
 protected:
     friend class CCLayerImpl;
     friend class TreeSynchronizer;
 
     LayerChromium();
 
     void setNeedsCommit();
 
+    IntRect layerRectToContentRect(const WebKit::WebRect& layerRect);
+
     // This flag is set when layer need repainting/updating.
     bool m_needsDisplay;
 
     // Tracks whether this layer may have changed stacking order with its siblings.
     bool m_stackingOrderChanged;
 
     // The update rect is the region of the compositor resource that was actually updated by the compositor.
     // For layers that may do updating outside the compositor's control (i.e. plugin layers), this information
     // is not available and the update rect will remain empty.
     // Note this rect is in layer space (not content space).
@@ skipping 89 matching lines @@
     WebKit::WebAnimationDelegate* m_layerAnimationDelegate;
     WebKit::WebLayerScrollClient* m_layerScrollClient;
 };
 
 void sortLayers(Vector<RefPtr<LayerChromium> >::iterator, Vector<RefPtr<LayerChromium> >::iterator, void*);
 
 }
 #endif // USE(ACCELERATED_COMPOSITING)
 
 #endif