Change call-sites now that SkCanvas is not ref-counted

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 <stddef.h>
 #include <time.h>
 
@@ skipping 242 matching lines @@
 SkBaseDevice* BitmapPlatformDevice::onCreateDevice(const CreateInfo& cinfo,
                                                    const SkPaint*) {
   const SkImageInfo& info = cinfo.fInfo;
   const bool do_clear = !info.isOpaque();
   SkASSERT(info.colorType() == kN32_SkColorType);
   return Create(NULL, info.width(), info.height(), info.isOpaque(), do_clear);
 }
 
 // PlatformCanvas impl
 
-SkCanvas* CreatePlatformCanvas(CGContextRef ctx, int width, int height,
-                               bool is_opaque, OnFailureType failureType) {
+std::unique_ptr<SkCanvas> CreatePlatformCanvas(CGContextRef ctx,
+                                               int width,
+                                               int height,
+                                               bool is_opaque,
+                                               OnFailureType failureType) {
   const bool do_clear = false;
   sk_sp<SkBaseDevice> dev(
       BitmapPlatformDevice::Create(ctx, width, height, is_opaque, do_clear));
   return CreateCanvas(dev, failureType);
 }
 
-SkCanvas* CreatePlatformCanvas(int width, int height, bool is_opaque,
-                               uint8_t* data, OnFailureType failureType) {
+std::unique_ptr<SkCanvas> CreatePlatformCanvas(int width,
+                                               int height,
+                                               bool is_opaque,
+                                               uint8_t* data,
+                                               OnFailureType failureType) {
   sk_sp<SkBaseDevice> dev(
       BitmapPlatformDevice::CreateWithData(data, width, height, is_opaque));
   return CreateCanvas(dev, failureType);
 }
 
 }  // namespace skia