Limit manual control of platform painting

skia/ext/bitmap_platform_device_win.h

Index: skia/ext/bitmap_platform_device_win.h
diff --git a/skia/ext/bitmap_platform_device_win.h b/skia/ext/bitmap_platform_device_win.h
index 3f3a5e15f740e9dcbb15ca697405694472ea4945..263baac01e4d8294b2c66728b751d661b0166c3b 100644
--- a/skia/ext/bitmap_platform_device_win.h
+++ b/skia/ext/bitmap_platform_device_win.h
@@ -7,6 +7,7 @@
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
+#include "skia/ext/platform_canvas.h"
 #include "skia/ext/platform_device.h"
 #include "skia/ext/refptr.h"
 
@@ -38,14 +39,8 @@ class SK_API BitmapPlatformDevice : public SkBitmapDevice, public PlatformDevice
 
   ~BitmapPlatformDevice() override;
 
-  // PlatformDevice overrides
-  // Retrieves the bitmap DC, which is the memory DC for our bitmap data. The
-  // bitmap DC is lazy created.
-  PlatformSurface BeginPlatformPaint() override;
-  void EndPlatformPaint() override;
-
-  // Loads the given transform and clipping region into the HDC. This is
-  // overridden from SkBaseDevice.
+  // Loads (lazily) the given transform and clipping region into the HDC. This
+  // is overridden from SkBaseDevice, where it is deprecated.
   void setMatrixClip(const SkMatrix& transform,
                      const SkRegion& region,
                      const SkClipStack&) override;
@@ -53,6 +48,11 @@ class SK_API BitmapPlatformDevice : public SkBitmapDevice, public PlatformDevice
   void DrawToHDC(HDC dc, int x, int y, const RECT* src_rect) override;
 
  protected:
+  // PlatformDevice overrides
+  // Retrieves the bitmap DC, which is the memory DC for our bitmap data. The
+  // bitmap DC may be lazily created.
+  PlatformSurface BeginPlatformPaint() override;
+
   // Flushes the Windows device context so that the pixel data can be accessed
   // directly by Skia. Overridden from SkBaseDevice, this is called when Skia
   // starts accessing pixel data.
@@ -108,6 +108,7 @@ class SK_API BitmapPlatformDevice : public SkBitmapDevice, public PlatformDevice
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(BitmapPlatformDevice);
+  friend class skia::ScopedPlatformPaint;
 };
 
 }  // namespace skia