Media Remoting: Draw remoting interstitial on poster image.

content/renderer/image_downloader/single_image_downloader.h

Index: content/renderer/image_downloader/single_image_downloader.h
diff --git a/content/renderer/image_downloader/single_image_downloader.h b/content/renderer/image_downloader/single_image_downloader.h
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+++ b/content/renderer/image_downloader/single_image_downloader.h
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+// 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/memory/weak_ptr.h"
+#include "content/renderer/image_downloader/image_downloader_base.h"
+
+namespace content {
+
+// A one time image downloader that will download a single image. When there are
+// multiple frames, returns the first one. Returns an empty bitmap if
+// downloading fails. This class does not impose size limitation on the image.
+class SingleImageDownloader {
+ public:
+  using DownloadImageCallback = base::Callback<void(const SkBitmap&)>;
+
+  // Called to download the image in given |url|, and run |cb| when done.
+  // A new ImageDownloaderBase will be created and used to download the image,
+  // and will be destructed when downloading finishes or |render_frame| is
+  // destructed.
+  static void DownloadImage(base::WeakPtr<RenderFrame> render_frame,
+                            const GURL& url,
+                            const DownloadImageCallback& cb);
+
+ private:
+  // Callback when downloading finishes. |image_downloader| is passed in as a
+  // unique_ptr to keep it alive while downloading and destroy it after this
+  // callback is called.
+  static void DidDownloadImage(
+      std::unique_ptr<ImageDownloaderBase> image_downloader,
+      const DownloadImageCallback& callback,
+      int http_status_code,
+      const std::vector<SkBitmap>& images);
+
+  DISALLOW_COPY_AND_ASSIGN(SingleImageDownloader);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_IMAGE_DOWNLOADER_SINGLE_IMAGE_DOWNLOADER_H_