Limit manual control of platform painting

skia/ext/platform_canvas.cc

 // Copyright (c) 2011 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 "base/logging.h"
 #include "build/build_config.h"
 #include "skia/ext/platform_device.h"
 #include "third_party/skia/include/core/SkMetaData.h"
@@ skipping 47 matching lines @@
   }
 
   result->reset(info, pixels, row_bytes);
   return true;
 }
 
 bool SupportsPlatformPaint(const SkCanvas* canvas) {
   return GetPlatformDevice(GetTopDevice(*canvas)) != nullptr;
 }
 
-PlatformSurface BeginPlatformPaint(SkCanvas* canvas) {
-  PlatformDevice* platform_device = GetPlatformDevice(GetTopDevice(*canvas));
-  if (platform_device)
-    return platform_device->BeginPlatformPaint();
-
-  return 0;
-}
-
-void EndPlatformPaint(SkCanvas* canvas) {
-  PlatformDevice* platform_device = GetPlatformDevice(GetTopDevice(*canvas));
-  if (platform_device)
-    platform_device->EndPlatformPaint();
-}
-
 size_t PlatformCanvasStrideForWidth(unsigned width) {
   return 4 * width;
 }
 
 SkCanvas* CreateCanvas(const skia::RefPtr<SkBaseDevice>& device, OnFailureType failureType) {
   if (!device) {
     if (CRASH_ON_FAILURE == failureType)
       SK_CRASH();
     return nullptr;
   }
@@ skipping 17 matching lines @@
 
 CGContextRef GetBitmapContext(const SkCanvas& canvas) {
   SkBaseDevice* device = GetTopDevice(canvas);
   PlatformDevice* platform_device = GetPlatformDevice(device);
   return platform_device ?  platform_device->GetBitmapContext() :
       nullptr;
 }
 
 #endif
 
+ScopedPlatformPaint::ScopedPlatformPaint(SkCanvas* canvas) :
+    canvas_(canvas),
+    platform_surface_(nullptr) {
+  PlatformDevice* platform_device = GetPlatformDevice(GetTopDevice(*canvas));
+  if (platform_device)
+    platform_surface_ = platform_device->BeginPlatformPaint();
+}
+
+ScopedPlatformPaint::~ScopedPlatformPaint() { }
+
+PlatformSurface ScopedPlatformPaint::GetPlatformSurface() { return platform_surface_; }
+
+
 
 }  // namespace skia