cc/paint: Remove cc::PaintSurface.

ui/gfx/canvas.h

Index: ui/gfx/canvas.h
diff --git a/ui/gfx/canvas.h b/ui/gfx/canvas.h
index 4fcb4bcfbdfe563610198d12239de0f6e12ec6e4..1be056ac36ca0b85c771030b0fbb67d3607d3e90 100644
--- a/ui/gfx/canvas.h
+++ b/ui/gfx/canvas.h
@@ -14,7 +14,6 @@
 #include "base/strings/string16.h"
 #include "cc/paint/paint_canvas.h"
 #include "cc/paint/paint_flags.h"
-#include "cc/paint/paint_surface.h"
 #include "ui/gfx/image/image_skia.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/text_constants.h"
@@ -503,10 +502,10 @@ class GFX_EXPORT Canvas {
   float image_scale_;
 
   // canvas_ is our active canvas object. Sometimes we are also the owner,
-  // in which case surface_ will be set. Other times we are just
+  // in which case owned_canvas_ will be set. Other times we are just
   // borrowing someone else's canvas, in which case canvas_ will point there
-  // but surface_ will be null.
-  sk_sp<cc::PaintSurface> surface_;
+  // but owned_canvas_ will be null.
+  std::unique_ptr<cc::PaintCanvas> owned_canvas_;
   cc::PaintCanvas* canvas_;
 
   DISALLOW_COPY_AND_ASSIGN(Canvas);