Refactor image handling in Sky

sky/engine/core/loader/CanvasImageLoader.h

+// SKY_ENGINE_CORE_PAINTING_CANVASIMAGE_H_
+// Copyright 2015 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.
+
+#ifndef SKY_ENGINE_CORE_LOADER_CANVASIMAGELOADER_H_
+#define SKY_ENGINE_CORE_LOADER_CANVASIMAGELOADER_H_
+
+#include "mojo/common/data_pipe_drainer.h"
+#include "sky/engine/core/loader/ImageLoaderCallback.h"
+#include "sky/engine/platform/SharedBuffer.h"
+#include "sky/engine/platform/fetcher/MojoFetcher.h"
+#include "sky/engine/tonic/dart_wrappable.h"
+#include "sky/engine/wtf/OwnPtr.h"
+#include "sky/engine/wtf/text/AtomicString.h"
+
+namespace blink {
+
+class CanvasImageLoader : public MojoFetcher::Client,
+                          public mojo::common::DataPipeDrainer::Client,
+                          public RefCounted<CanvasImageLoader>,
+                          public DartWrappable {
+  DEFINE_WRAPPERTYPEINFO();
+ public:
+  static PassRefPtr<CanvasImageLoader> create(const String& src, PassOwnPtr<ImageLoaderCallback> callback)
+  {
+    return adoptRef(new CanvasImageLoader(src, callback));
+  }
+  virtual ~CanvasImageLoader();
+
+  void load();
+
+  // MojoFetcher::Client
+  void OnReceivedResponse(mojo::URLResponsePtr) override;
+
+  // mojo::common::DataPipeDrainer::Client
+  void OnDataAvailable(const void*, size_t) override;
+  void OnDataComplete() override;
+
+ private:
+  explicit CanvasImageLoader(const String& src, PassOwnPtr<ImageLoaderCallback> callback);
+
+  OwnPtr<MojoFetcher> fetcher_;
+  OwnPtr<mojo::common::DataPipeDrainer> drainer_;
+  RefPtr<SharedBuffer> buffer_;
+
+  KURL url_;
+  OwnPtr<ImageLoaderCallback> callback_;
+};
+
+}  // namespace blink
+
+#endif  // SKY_ENGINE_CORE_LOADER_CANVASIMAGELOADER_H_