Pass accurate contentsScale to LayerImpl.

cc/layer.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
 
 #include "FloatPoint.h"
 #include "Region.h"
 #include "base/memory/ref_counted.h"
@@ skipping 171 matching lines @@
     bool hasMask() const { return m_maskLayer; }
     bool hasReplica() const { return m_replicaLayer; }
     bool replicaHasMask() const { return m_replicaLayer && (m_maskLayer || m_replicaLayer->m_maskLayer); }
 
     // These methods typically need to be overwritten by derived classes.
     virtual bool drawsContent() const;
     virtual void update(ResourceUpdateQueue&, const OcclusionTracker*, RenderingStats&) { }
     virtual bool needMoreUpdates();
     virtual void setIsMask(bool) { }
     virtual void bindContentsTexture() { }
-    virtual bool needsContentsScale() const;
 
     void setDebugBorderColor(SkColor);
     void setDebugBorderWidth(float);
     void setDebugName(const std::string&);
 
     virtual void pushPropertiesTo(LayerImpl*);
 
     void clearRenderSurface() { m_renderSurface.reset(); }
     RenderSurface* renderSurface() const { return m_renderSurface.get(); }
     void createRenderSurface();
@@ skipping 19 matching lines @@
     void setDrawTransform(const WebKit::WebTransformationMatrix& matrix) { m_drawTransform = matrix; }
     // This moves from content space, with origin the top left to screen space with origin in the top left.
     // It converts logical, non-page-scaled pixels to physical pixels.
     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);
+    // By default contentsScale is forced to be 1 except for subclasses of ContentsScalingLayer.
+    virtual float contentsScaleX() const;
+    virtual float contentsScaleY() const;
+    virtual void setContentsScale(float contentsScale) { }
 
     // The scale at which contents should be rastered, to match the scale at
     // which they will drawn to the screen. This scale is a component of the
     // contentsScale() but does not include page/device scale factors.
     float rasterScale() const { return m_rasterScale; }
     void setRasterScale(float scale);
 
     // When true, the rasterScale() will be set by the compositor. If false, it
     // will use whatever value is given to it by the embedder.
     bool automaticallyComputeRasterScale() { return m_automaticallyComputeRasterScale; }
@@ skipping 29 matching lines @@
 
     bool hasActiveAnimation() const;
 
     virtual void notifyAnimationStarted(const AnimationEvent&, double wallClockTime);
     virtual void notifyAnimationFinished(double wallClockTime);
 
     virtual Region visibleContentOpaqueRegion() const;
 
     virtual ScrollbarLayer* toScrollbarLayer();
 
+    IntRect layerRectToContentRect(const FloatRect& layerRect) const;
+
 protected:
     friend class LayerImpl;
     friend class TreeSynchronizer;
     virtual ~Layer();
 
     Layer();
 
     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 79 matching lines @@
 
     Layer* m_renderTarget;
 
     WebKit::WebTransformationMatrix m_drawTransform;
     WebKit::WebTransformationMatrix m_screenSpaceTransform;
     bool m_drawTransformIsAnimating;
     bool m_screenSpaceTransformIsAnimating;
 
     // Uses target surface space.
     IntRect m_drawableContentRect;
-    float m_contentsScale;
     float m_rasterScale;
     bool m_automaticallyComputeRasterScale;
     bool m_boundsContainPageScale;
 
     WebKit::WebTransformationMatrix m_implTransform;
 
     WebKit::WebAnimationDelegate* m_layerAnimationDelegate;
     WebKit::WebLayerScrollClient* m_layerScrollClient;
 };
 
 void sortLayers(std::vector<scoped_refptr<Layer> >::iterator, std::vector<scoped_refptr<Layer> >::iterator, void*);
 
 }  // namespace cc
 
 #endif