Add utility for converting SkCanvas to CGContext

skia/ext/skia_utils_mac.h

 // Copyright (c) 2006-2008 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.
 
 #ifndef SKIA_EXT_SKIA_UTILS_MAC_H_
 #define SKIA_EXT_SKIA_UTILS_MAC_H_
 #pragma once
 
 #include <CoreGraphics/CGColor.h>
 #include <vector>
 
 #include "third_party/skia/include/core/SkColor.h"
 
 struct SkIRect;
 struct SkPoint;
 struct SkRect;
 class SkBitmap;
+class SkCanvas;
 class SkMatrix;
 #ifdef __LP64__
 typedef CGSize NSSize;
 #else
 typedef struct _NSSize NSSize;
 #endif
 
 #ifdef __OBJC__
 @class NSImage;
 @class NSImageRep;
@@ skipping 51 matching lines @@
 // TODO(thakis): Remove this -- http://crbug.com/69432
 NSImage* SkBitmapToNSImage(const SkBitmap& icon);
 
 // Given a vector of SkBitmaps, return an NSImage with each bitmap added
 // as a representation.
 NSImage* SkBitmapsToNSImage(const std::vector<const SkBitmap*>& bitmaps);
 
 // Returns |[NSImage imageNamed:@"NSApplicationIcon"]| as SkBitmap.
 SkBitmap AppplicationIconAtSize(int size);
 
+// Converts a SkCanvas temporarily to a CGContext
+class SkiaBitLocker {
+ public:
+  explicit SkiaBitLocker(SkCanvas* canvas);
+  ~SkiaBitLocker();
+  CGContextRef cgContext();
+
+ private:
+  void releaseIfNeeded();
+  SkCanvas* canvas_;
+  CGContextRef cgContext_;
+};
+
+
 }  // namespace gfx
 
 #endif  // SKIA_EXT_SKIA_UTILS_MAC_H_