[Chromecast] Support blocking some video resolutions

chromecast/browser/media/video_resolution_policy.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 CHROMECAST_BROWSER_MEDIA_VIDEO_RESOLUTION_POLICY_H_
+#define CHROMECAST_BROWSER_MEDIA_VIDEO_RESOLUTION_POLICY_H_
+
+#include "base/macros.h"
+
+namespace gfx {
+class Size;
+}  // namespace gfx
+
+namespace chromecast {
+namespace media {
+
+// Interface allowing renderer to check for whether certain video resolutions
+// should have playback blocked.
+// TODO(halliwell): remove this mechanism once we have PR3.

[servolk, 2016/08/26 22:36:22]

Nit: if there's a tracking bug for this, let's mention it here.

+class VideoResolutionPolicy {
+ public:
+  // Observer allows policy subclass to notify renderer when some
+  // conditions have changed.  Renderer should re-check current
+  // resolution.
+  class Observer {
+   public:
+    virtual void OnVideoResolutionPolicyChanged() = 0;
+
+   protected:
+    virtual ~Observer() {}
+  };
+
+  virtual ~VideoResolutionPolicy();
+
+  virtual void AddObserver(Observer* observer) = 0;
+  virtual void RemoveObserver(Observer* observer) = 0;
+
+  virtual bool ShouldBlock(const gfx::Size& size) = 0;
+};
+
+}  // namespace media
+}  // namespace chromecast
+
+#endif  // CHROMECAST_BROWSER_MEDIA_VIDEO_RESOLUTION_POLICY_H_