Allow the creation of a skia::PlatformCanvas from a CGContextRef.

skia/ext/platform_canvas_mac.cc

 // 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.
 
 #include "skia/ext/platform_canvas.h"
 
 #include "skia/ext/bitmap_platform_device_mac.h"
 #include "third_party/skia/include/core/SkTypes.h"
 
 namespace skia {
 
 PlatformCanvas::PlatformCanvas(int width, int height, bool is_opaque)
     : SkCanvas(SkNEW(BitmapPlatformDeviceFactory)) {
   initialize(width, height, is_opaque);
 }
 
 PlatformCanvas::PlatformCanvas(int width,
                                int height,
                                bool is_opaque,
                                CGContextRef context)
     : SkCanvas(SkNEW(BitmapPlatformDeviceFactory)) {
-  initialize(width, height, is_opaque);
+  initialize(context, width, height, is_opaque);
 }
 
 PlatformCanvas::PlatformCanvas(int width,
                                int height,
                                bool is_opaque,
                                uint8_t* data)
     : SkCanvas(SkNEW(BitmapPlatformDeviceFactory)) {
   initialize(width, height, is_opaque, data);
 }
 
 PlatformCanvas::~PlatformCanvas() {
 }
 
 bool PlatformCanvas::initialize(int width,
                                 int height,
                                 bool is_opaque,
                                 uint8_t* data) {
-  SkDevice* device = BitmapPlatformDevice::CreateWithData(data, width, height,
-                                                          is_opaque);
+  return initialize(BitmapPlatformDevice::CreateWithData(data, width, height,
+                                                         is_opaque));
+}
+
+bool PlatformCanvas::initialize(CGContextRef context,
+                                int width,
+                                int height,
+                                bool is_opaque) {
+  return initialize(BitmapPlatformDevice::Create(context, width, height,
+                                                 is_opaque));
+}
+
+bool PlatformCanvas::initialize(SkDevice* device) {
   if (!device)
     return false;
 
   setDevice(device);
   device->unref();  // Was created with refcount 1, and setDevice also refs.
   return true;
 }
 
 CGContextRef PlatformCanvas::beginPlatformPaint() {
   return getTopPlatformDevice().GetBitmapContext();
 }
 
 void PlatformCanvas::endPlatformPaint() {
   // Flushing will be done in onAccessBitmap.
 }
 
 }  // namespace skia