Move DIP translation from ui/aura to ui/compositor

ui/gfx/compositor/compositor.h

Index: ui/gfx/compositor/compositor.h
diff --git a/ui/gfx/compositor/compositor.h b/ui/gfx/compositor/compositor.h
index 9475cf62445acfe2de8b85b8450cbaba2fe1cf07..aef2e040b0d4fa9f7f32eba03e07cd8e6d9a4940 100644
--- a/ui/gfx/compositor/compositor.h
+++ b/ui/gfx/compositor/compositor.h
@@ -111,7 +111,7 @@ class COMPOSITOR_EXPORT Texture : public base::RefCounted<Texture> {
 
   unsigned int texture_id_;
   bool flipped_;
-  gfx::Size size_;
+  gfx::Size size_;  // in pixel
 
   DISALLOW_COPY_AND_ASSIGN(Texture);
 };
@@ -135,8 +135,7 @@ class COMPOSITOR_EXPORT Compositor
     : NON_EXPORTED_BASE(public WebKit::WebLayerTreeViewClient) {
  public:
   Compositor(CompositorDelegate* delegate,
-             gfx::AcceleratedWidget widget,
-             const gfx::Size& size);
+             gfx::AcceleratedWidget widget);
   virtual ~Compositor();
 
   static void Initialize(bool useThread);
@@ -154,6 +153,10 @@ class COMPOSITOR_EXPORT Compositor
   Layer* root_layer() { return root_layer_; }
   void SetRootLayer(Layer* root_layer);
 
+  // The scale factor of the device that this compositor is
+  // compositing layers on.
+  float device_scale_factor() const { return device_scale_factor_; }
+
   // Draws the scene created by the layer tree and any visual effects. If
   // |force_clear| is true, this will cause the compositor to clear before
   // compositing.
@@ -164,16 +167,16 @@ class COMPOSITOR_EXPORT Compositor
   // the whole frame needs to be drawn.
   void ScheduleFullDraw();
 
-  // Reads the region |bounds| of the contents of the last rendered frame
-  // into the given bitmap.
+  // Reads the region |bounds_in_pixel| of the contents of the last rendered
+  // frame into the given bitmap.
   // Returns false if the pixels could not be read.
-  bool ReadPixels(SkBitmap* bitmap, const gfx::Rect& bounds);
+  bool ReadPixels(SkBitmap* bitmap, const gfx::Rect& bounds_in_pixel);
 
-  // Notifies the compositor that the size of the widget that it is
-  // drawing to has changed.
-  void WidgetSizeChanged(const gfx::Size& size);
+  // Notifies the compositor that the device scale factor and size of
+  // the widget that it is drawing to has changed.
+  void WidgetScaleOrSizeChanged(float scale, const gfx::Size& size_in_pixel);
 
-  // Returns the size of the widget that is being drawn to.
+  // Returns the size of the widget that is being drawn to in pixel coordinates.
   const gfx::Size& size() const { return size_; }
 
   // Returns the widget for this compositor.
@@ -201,6 +204,11 @@ class COMPOSITOR_EXPORT Compositor
   // Signals swap has aborted (e.g. lost context).
   void OnSwapBuffersAborted();
 
+  // Translates |transform| with translate_offset, then apply the
+  // device scale factor to the all translate operations in the transform.
+  Transform GetTranslateTransform(const Transform& transform,
+                                  const gfx::Point& translate_offset);
+
   // WebLayerTreeViewClient implementation.
   virtual void updateAnimations(double frameBeginTime);
   virtual void layout();
@@ -237,6 +245,12 @@ class COMPOSITOR_EXPORT Compositor
   // for completion.
   bool swap_posted_;
 
+  float device_scale_factor_;
+
+  // Transforms to scale the translation in |transform_|.
+  Transform scale_translate_;
+  Transform invese_scale_translate_;

[piman, 2012/05/04 18:46:06]

nit: invese->inverse

+
   friend class base::RefCounted<Compositor>;
 };