Media Remoting: Draw remoting interstitial on poster image.

content/renderer/image_downloader/single_image_downloader.h

+// Copyright 2016 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 CONTENT_RENDERER_IMAGE_DOWNLOADER_SINGLE_IMAGE_DOWNLOADER_H_
+#define CONTENT_RENDERER_IMAGE_DOWNLOADER_SINGLE_IMAGE_DOWNLOADER_H_
+
+#include "base/callback.h"
+#include "base/memory/weak_ptr.h"
+#include "content/public/renderer/render_frame_observer.h"
+#include "content/renderer/image_downloader/image_downloader_core.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "url/gurl.h"
+
+namespace content {
+
+class ImageDownloaderCore;
+class RenderFrame;
+
+// A one time image downloader that will be self-destructed when downloading
+// finishes or the |render_frame| is destructed. When there are multiple frames,
+// return the first one.
+class SingleImageDownloader : public RenderFrameObserver {
+ public:
+  using DownloadImageCallback = base::Callback<void(const SkBitmap&)>;
+
+  // Called to download the image in given |url|, and run |cb| when done.
+  // A new SingleImageDownloader will be created, and be self-destructed when
+  // downloading finishes or |render_frame| is destructed.
+  static void DownloadImage(const base::WeakPtr<RenderFrame>& render_frame,
+                            const GURL& url,
+                            const DownloadImageCallback& cb);
+
+  ~SingleImageDownloader() override;
+
+ private:
+  SingleImageDownloader(RenderFrame* render_frame,
+                        const GURL& url,
+                        bool is_favicon,
+                        bool bypass_cache,
+                        const DownloadImageCallback& callback);
+
+  // RenderFrameObserver implementation.
+  void OnDestruct() override;
+
+  // Called by |image_downloader_| when downloading finishes.
+  void DidDownloadImage(const DownloadImageCallback& callback,
+                        int http_status_code,
+                        const std::vector<SkBitmap>& images);
+
+  ImageDownloaderCore image_downloader_;
+
+  DISALLOW_COPY_AND_ASSIGN(SingleImageDownloader);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_IMAGE_DOWNLOADER_SINGLE_IMAGE_DOWNLOADER_H_