Simplify platform_canvas.h by recognizing that PlatformCanvas does not actually extend

skia/ext/platform_canvas_skia.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/platform_canvas.h"
 
 #include "base/debug/trace_event.h"
 #include "skia/ext/bitmap_platform_device.h"
 
 // TODO(reveman): a lot of unnecessary duplication of code from
 // platform_canvas_[win|linux|mac].cc in here. Need to refactor
 // PlatformCanvas to avoid this:
 // http://code.google.com/p/chromium/issues/detail?id=119555
 
 namespace skia {
-
+#if 0
 PlatformCanvas::PlatformCanvas(int width, int height, bool is_opaque) {
   TRACE_EVENT2("skia", "PlatformCanvas::PlatformCanvas",
                "width", width, "height", height);
   if (!initialize(width, height, is_opaque))
     SK_CRASH();
 }
 
 #if defined(WIN32)
 PlatformCanvas::PlatformCanvas(int width,
                                int height,
@@ skipping 75 matching lines @@
                                 uint8_t* data) {
   // Use platform specific device for data.
   if (data)
     return initializeWithDevice(BitmapPlatformDevice::Create(
         width, height, is_opaque, data));
 
   return initializeWithDevice(new SkDevice(
       SkBitmap::kARGB_8888_Config, width, height, is_opaque));
 }
 #endif
-
+#endif
 }  // namespace skia