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..92c332bd2e0f06912001263c87ab0682fe0d3ea5 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_info.h"
 #include "ui/events/event.h"
 #include "ui/events/event_target.h"
 #include "ui/gfx/geometry/insets.h"
@@ -61,6 +62,7 @@ class InputMethod;
 class Layer;
 class NativeTheme;
 class PaintContext;
+// class PaintInfo;
 class ThemeProvider;
 class TransformRecorder;
 }
@@ -543,7 +545,7 @@ class VIEWS_EXPORT View : public ui::LayerDelegate,
   // for View coordinates and language direction as required, allows the View
   // to paint itself via the various OnPaint*() event handlers and then paints
   // the hierarchy beneath it.
-  void Paint(const ui::PaintContext& parent_context);
+  void Paint(const ui::PaintInfo& parent_paint_info);
 
   // The background object may be null.
   void SetBackground(std::unique_ptr<Background> b);
@@ -1152,7 +1154,7 @@ class VIEWS_EXPORT View : public ui::LayerDelegate,
 
   // Responsible for calling Paint() on child Views. Override to control the
   // order child Views are painted.
-  virtual void PaintChildren(const ui::PaintContext& context);
+  virtual void PaintChildren(const ui::PaintInfo& info);
 
   // Override to provide rendering in any part of the View's bounds. Typically
   // this is the "contents" of the view. If you override this method you will
@@ -1271,6 +1273,12 @@ 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::PaintInfo::ScaleType.
+  virtual ui::PaintInfo::ScaleType GetPaintScaleType() const;
+
   // Debugging -----------------------------------------------------------------
 
 #if !defined(NDEBUG)
@@ -1319,17 +1327,19 @@ 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 |PaintInfo|
   // for this view.
-  gfx::Vector2d GetPaintContextOffset() const;
+  gfx::Rect GetPaintRecordingBounds() 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.
-  void RecursivePaintHelper(void (View::*func)(const ui::PaintContext&),
-                            const ui::PaintContext& context);
+  void RecursivePaintHelper(void (View::*func)(const ui::PaintInfo&),
+                            const ui::PaintInfo& info);
 
   // Invokes Paint() and, if necessary, PaintDebugRects().  Should be called
   // only on the root of a widget/layer.  PaintDebugRects() is invoked as a
@@ -1340,7 +1350,7 @@ class VIEWS_EXPORT View : public ui::LayerDelegate,
   // Draws a semitransparent rect to indicate the bounds of this view.
   // Recursively does the same for all children.  Invoked only with
   // --draw-view-bounds-rects.
-  void PaintDebugRects(const ui::PaintContext& parent_context);
+  void PaintDebugRects(const ui::PaintInfo& paint_info);
 
   // Tree operations -----------------------------------------------------------