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

ui/compositor/layer.cc

Index: ui/compositor/layer.cc
diff --git a/ui/compositor/layer.cc b/ui/compositor/layer.cc
index 16505f304bb7a25caa92884d59864ed7822047df..73e26ae8052441df7ad45bb46f251828d77e2687 100644
--- a/ui/compositor/layer.cc
+++ b/ui/compositor/layer.cc
@@ -29,6 +29,7 @@
 #include "ui/compositor/compositor_switches.h"
 #include "ui/compositor/dip_util.h"
 #include "ui/compositor/layer_animator.h"
+#include "ui/compositor/paint_context.h"
 #include "ui/gfx/animation/animation.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/display.h"
@@ -78,8 +79,7 @@ Layer::Layer()
       delegate_(NULL),
       owner_(NULL),
       cc_layer_(NULL),
-      device_scale_factor_(1.0f),
-      inside_paint_(false) {
+      device_scale_factor_(1.0f) {
   CreateCcLayer();
 }
 
@@ -103,8 +103,7 @@ Layer::Layer(LayerType type)
       delegate_(NULL),
       owner_(NULL),
       cc_layer_(NULL),
-      device_scale_factor_(1.0f),
-      inside_paint_(false) {
+      device_scale_factor_(1.0f) {
   CreateCcLayer();
 }
 
@@ -748,11 +747,8 @@ void Layer::PaintContents(
   TRACE_EVENT1("ui", "Layer::PaintContents", "name", name_);
   scoped_ptr<gfx::Canvas> canvas(gfx::Canvas::CreateCanvasWithoutScaling(
       sk_canvas, device_scale_factor_));
-  if (delegate_) {
-    base::AutoReset<bool> inside_paint(&inside_paint_, true);
-    paint_rect_ = clip;
-    delegate_->OnPaintLayer(canvas.get());
-  }
+  if (delegate_)
+    delegate_->OnPaintLayer(PaintContext(canvas.get(), clip));
 }
 
 scoped_refptr<cc::DisplayItemList> Layer::PaintContentsToDisplayList(
@@ -783,11 +779,6 @@ void Layer::SetForceRenderSurface(bool force) {
   cc_layer_->SetForceRenderSurface(force_render_surface_);
 }
 
-gfx::Rect Layer::PaintRect() const {
-  DCHECK(inside_paint_);
-  return paint_rect_;
-}
-
 class LayerDebugInfo : public base::trace_event::ConvertableToTraceFormat {
  public:
   explicit LayerDebugInfo(std::string name) : name_(name) { }