Support for defered media load to cast_content_render_client.

chromecast/renderer/cast_media_load_deferrer.h

+// Copyright 2014 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 CHROMECAST_RENDERER_CAST_MEDIA_LOAD_DEFERRER_H_
+#define CHROMECAST_RENDERER_CAST_MEDIA_LOAD_DEFERRER_H_
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "content/public/renderer/render_frame_observer.h"
+
+namespace chromecast {
+
+// Defers media player loading in background web apps until brought into
+// foreground.
+class CastMediaLoadDeferrer : public content::RenderFrameObserver {
+ public:
+  // Will run |closure| to continue loading the media resource once the page is
+  // swapped in.
+  CastMediaLoadDeferrer(content::RenderFrame* render_frame,
+                        const base::Closure& continue_loading_cb);
+  ~CastMediaLoadDeferrer() override;
+
+ private:
+  // content::RenderFrameObserver implementation:
+  void WasShown() override;
+
+  base::Closure continue_loading_cb_;
+
+  DISALLOW_COPY_AND_ASSIGN(CastMediaLoadDeferrer);
+};
+
+}  // namespace chromecast
+
+#endif  // CHROMECAST_RENDERER_CAST_MEDIA_LOAD_DEFERRER_H_