Implements core logic for Pixel Canvas

ui/views/view.h

Index: ui/views/view.h
diff --git a/ui/views/view.h b/ui/views/view.h
index 7a8a7b327ebb5627de5a291fa7d0c06d35e3162e..7ac097f5102728ff4191743fabdead12176ff1fa 100644
--- a/ui/views/view.h
+++ b/ui/views/view.h
@@ -29,6 +29,7 @@
 #include "ui/compositor/layer_delegate.h"
 #include "ui/compositor/layer_owner.h"
 #include "ui/compositor/paint_cache.h"
+#include "ui/compositor/paint_context.h"
 #include "ui/events/event.h"
 #include "ui/events/event_target.h"
 #include "ui/gfx/geometry/insets.h"
@@ -1271,6 +1272,12 @@ class VIEWS_EXPORT View : public ui::LayerDelegate,
   // hierarchy).
   virtual void OnNativeThemeChanged(const ui::NativeTheme* theme) {}
 
+  // Pixel Canvas --------------------------------------------------------------
+
+  // Returns the type of scaling to be done for this View. Values should be from
+  // ui::PaintContext::ScaleType.
+  virtual ui::PaintContext::ScaleType GetContextScaleType() const;
+
   // Debugging -----------------------------------------------------------------
 
 #if !defined(NDEBUG)
@@ -1319,12 +1326,14 @@ class VIEWS_EXPORT View : public ui::LayerDelegate,
   // during painting.
   bool ShouldPaint() const;
 
-  // Returns the offset that should be used when constructing the paint context
+  // Returns the bounds that should be used when constructing the paint context
   // for this view.
-  gfx::Vector2d GetPaintContextOffset() const;
+  gfx::Rect GetPaintContextBounds() const;
 
   // Adjusts the transform of |recorder| in advance of painting.
-  void SetupTransformRecorderForPainting(ui::TransformRecorder* recorder) const;
+  void SetupTransformRecorderForPainting(
+      ui::TransformRecorder* recorder,
+      const gfx::Vector2d& offset_from_parent) const;
 
   // Recursively calls the painting method |func| on all non-layered children,
   // in Z order.