Pass a ui::PaintContext from ui::Layer to layer delegates.

ui/views/view.cc

 // Copyright (c) 2012 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.
 
 #define _USE_MATH_DEFINES // For VC++ to get M_PI. This has to be first.
 
 #include "ui/views/view.h"
 
 #include <algorithm>
 #include <cmath>
@@ skipping 1429 matching lines @@
     SetLayerBounds(GetLocalBounds() + offset);
   } else {
     for (int i = 0, count = child_count(); i < count; ++i) {
       View* child = child_at(i);
       child->UpdateChildLayerBounds(
           offset + gfx::Vector2d(child->GetMirroredX(), child->y()));
     }
   }
 }
 
-void View::OnPaintLayer(gfx::Canvas* canvas) {
+void View::OnPaintLayer(const ui::PaintContext& context) {
   if (!layer()->fills_bounds_opaquely())
-    canvas->DrawColor(SK_ColorBLACK, SkXfermode::kClear_Mode);
+    context.canvas()->DrawColor(SK_ColorBLACK, SkXfermode::kClear_Mode);
   if (!visible_)
     return;
-  Paint(ui::PaintContext(canvas, layer()->PaintRect()));
+  Paint(context);
 }
 
 void View::OnDelegatedFrameDamage(
     const gfx::Rect& damage_rect_in_dip) {
 }
 
 void View::OnDeviceScaleFactorChanged(float device_scale_factor) {
   snap_layer_to_pixel_boundary_ =
       (device_scale_factor - std::floor(device_scale_factor)) != 0.0f;
   SnapLayerToPixelBoundary();
@@ skipping 890 matching lines @@
   // Message the RootView to do the drag and drop. That way if we're removed
   // the RootView can detect it and avoid calling us back.
   gfx::Point widget_location(event.location());
   ConvertPointToWidget(this, &widget_location);
   widget->RunShellDrag(this, data, widget_location, drag_operations, source);
   // WARNING: we may have been deleted.
   return true;
 }
 
 }  // namespace views