call clear() instead of using deprecated API accessBitmap()

skia/ext/bitmap_platform_device_mac.cc

 // Copyright (c) 2012 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/bitmap_platform_device_mac.h"
 
 #import <ApplicationServices/ApplicationServices.h>
 #include <time.h>
 
 #include "base/mac/mac_util.h"
@@ skipping 128 matching lines @@
   CGContextRelease(context);
 
   return rv;
 }
 
 BitmapPlatformDevice* BitmapPlatformDevice::CreateAndClear(int width,
                                                            int height,
                                                            bool is_opaque) {
   BitmapPlatformDevice* device = Create(NULL, width, height, is_opaque);
   if (!is_opaque)
-    device->accessBitmap(true).eraseARGB(0, 0, 0, 0);
+    device->clear(0);
   return device;
 }
 
 BitmapPlatformDevice* BitmapPlatformDevice::CreateWithData(uint8_t* data,
                                                            int width,
                                                            int height,
                                                            bool is_opaque) {
   CGContextRef context = NULL;
   if (data)
     context = CGContextForData(data, width, height);
@@ skipping 122 matching lines @@
 
   if (!is_opaque)
     bitmap_.eraseColor(0);
 
   surface_ = CGContextForData(bitmap_.getPixels(), bitmap_.width(),
                               bitmap_.height());
   return true;
 }
 
 }  // namespace skia