add peekPixels to SkCanvas and SkSurface

gm/deviceproperties.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "gm.h"
+#include "SkBitmapDevice.h"
 #include "SkTypeface.h"
 
 namespace skiagm {
 
 class DevicePropertiesGM : public GM {
 public:
     DevicePropertiesGM() {
         this->setBGColor(0xFFFFFFFF);
     }
 
@@ skipping 85 matching lines @@
 private:
     typedef GM INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 static GM* MyFactory(void*) { return new DevicePropertiesGM; }
 static GMRegistry reg(MyFactory);
 
 }