don't need native-drawing-context for CanvasSkiaPaint

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 f29a6afa4eb05594b1b39a25ac9d113b80690f5c..6b2cd66c3fd3894754a56034aa470d109aa1f0ce 100644
--- a/ui/gfx/canvas_paint_mac.mm
+++ b/ui/gfx/canvas_paint_mac.mm
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "base/mac/mac_util.h"
+#include "third_party/skia/include/utils/mac/SkCGUtils.h"
 #include "ui/gfx/canvas_paint_mac.h"
 #include "ui/gfx/geometry/size.h"
 
@@ -25,9 +27,12 @@ CanvasSkiaPaint::~CanvasSkiaPaint() {
     canvas->restoreToCount(1);
 
     // Blit the dirty rect to the current context.
-    skia::ScopedPlatformPaint spp(canvas);
-    CGImageRef image =
-        CGBitmapContextCreateImage(spp.GetNativeDrawingContext());
+    SkPixmap pixmap;
+    bool peek = canvas->peekPixels(&pixmap);

[f(malita), 2017/01/04 14:31:36]

DCHECK(peek)?

[reed1, 2017/01/04 14:48:22]

Done.

+    SkBitmap bitmap;
+    bitmap.installPixels(pixmap);
+    CGImageRef image = SkCreateCGImageRefWithColorspace(
+        bitmap, base::mac::GetSystemColorSpace());
     CGRect dest_rect = NSRectToCGRect(rectangle_);
 
     CGContextRef destination_context =