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

skia/ext/platform_canvas_linux.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/debug/trace_event.h"
-#include "skia/ext/bitmap_platform_device.h"
-#include "skia/ext/platform_device.h"
-#include "third_party/skia/include/core/SkTypes.h"
-
-namespace skia {
-
-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();
-}
-
-PlatformCanvas::PlatformCanvas(int width, int height, bool is_opaque,
-                               uint8_t* data) {
-  TRACE_EVENT2("skia", "PlatformCanvas::PlatformCanvas",
-               "width", width, "height", height);
-  if (!initialize(width, height, is_opaque, data))
-    SK_CRASH();
-}
-
-PlatformCanvas::~PlatformCanvas() {
-}
-
-bool PlatformCanvas::initialize(int width, int height, bool is_opaque,
-                                uint8_t* data) {
-  return initializeWithDevice(BitmapPlatformDevice::Create(
-      width, height, is_opaque, data));
-}
-
-}  // namespace skia