Add skia::RefPtr class to wrap ref counted classes from Skia.

skia/ext/vector_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/vector_canvas.h"
 #include "third_party/skia/include/core/SkDevice.h"
 
 namespace skia {
 
-VectorCanvas::VectorCanvas(SkDevice* device) {
-  setDevice(device)->unref(); // Created with refcount 1, and setDevice refs.
+VectorCanvas::VectorCanvas(SkDevice* device)
+    : PlatformCanvas(device) {
 }
 
 VectorCanvas::~VectorCanvas() {
 }
 
 SkBounder* VectorCanvas::setBounder(SkBounder* bounder) {
   if (!IsTopDeviceVectorial())
     return PlatformCanvas::setBounder(bounder);
 
   // This function isn't used in the code. Verify this assumption.
   SkASSERT(false);
   return NULL;
 }
 
 SkDrawFilter* VectorCanvas::setDrawFilter(SkDrawFilter* filter) {
   // This function isn't used in the code. Verify this assumption.
   SkASSERT(false);
   return NULL;
 }
 
 bool VectorCanvas::IsTopDeviceVectorial() const {
   SkDevice* device = GetTopDevice(*this);
   return device->getDeviceCapabilities() & SkDevice::kVector_Capability;
 }
 
 }  // namespace skia