Rename paint data structures

ui/gfx/canvas_paint_mac.mm

Index: ui/gfx/canvas_paint_mac.mm
diff --git a/ui/gfx/canvas_paint_mac.mm b/ui/gfx/canvas_paint_mac.mm
index 73ed62abc6c348be272fb96c967c4a98454975ea..8cba450434157133ccd8c755e4f293abb4a4d6dd 100644
--- a/ui/gfx/canvas_paint_mac.mm
+++ b/ui/gfx/canvas_paint_mac.mm
@@ -23,7 +23,7 @@ CanvasSkiaPaint::CanvasSkiaPaint(NSRect dirtyRect, bool opaque)
 
 CanvasSkiaPaint::~CanvasSkiaPaint() {
   if (!is_empty()) {
-    SkCanvas* canvas = sk_canvas();
+    cc::PaintCanvas* canvas = sk_canvas();
     canvas->restoreToCount(1);
 
     // Blit the dirty rect to the current context.
@@ -68,7 +68,7 @@ void CanvasSkiaPaint::Init(bool opaque) {
 
   gfx::Size size(NSWidth(rectangle_), NSHeight(rectangle_));
   RecreateBackingCanvas(size, scale, opaque);
-  SkCanvas* canvas = sk_canvas();
+  cc::PaintCanvas* canvas = sk_canvas();
   canvas->clear(SkColorSetARGB(0, 0, 0, 0));
 
     // Need to translate so that the dirty region appears at the origin of the