Plugin Power Saver: Mute throttled plugins.

content/renderer/pepper/plugin_instance_throttler_impl.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 CONTENT_RENDERER_PEPPER_PLUGIN_INSTANCE_THROTTLER_IMPL_H_
 #define CONTENT_RENDERER_PEPPER_PLUGIN_INSTANCE_THROTTLER_IMPL_H_
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
+#include "base/timer/timer.h"
 #include "content/common/content_export.h"
 #include "content/public/renderer/plugin_instance_throttler.h"
 #include "ppapi/shared_impl/ppb_view_shared.h"
+#include "third_party/skia/include/core/SkBitmap.h"
 
 namespace blink {
 class WebInputEvent;
 struct WebRect;
 }
 
 namespace content {
 
 class RenderFrameImpl;
 
 class CONTENT_EXPORT PluginInstanceThrottlerImpl
     : public PluginInstanceThrottler {
  public:
   PluginInstanceThrottlerImpl(bool power_saver_enabled);
 
   ~PluginInstanceThrottlerImpl() override;
 
   // PluginInstanceThrottler implementation:
   void AddObserver(Observer* observer) override;
   void RemoveObserver(Observer* observer) override;
   bool IsThrottled() const override;
   bool IsHiddenForPlaceholder() const override;
   void MarkPluginEssential(PowerSaverUnthrottleMethod method) override;
   void SetHiddenForPlaceholder(bool hidden) override;
   blink::WebPlugin* GetWebPlugin() const override;
+  void NotifyAudioThrottled() override;
 
   void SetWebPlugin(blink::WebPlugin* web_plugin);
 
   bool needs_representative_keyframe() const {
     return state_ == THROTTLER_STATE_AWAITING_KEYFRAME;
   }
 
   bool power_saver_enabled() const {
     return state_ == THROTTLER_STATE_AWAITING_KEYFRAME ||
            state_ == THROTTLER_STATE_PLUGIN_THROTTLED;
@@ skipping 24 matching lines @@
     // A representative keyframe has been chosen and the plugin is throttled.
     THROTTLER_STATE_PLUGIN_THROTTLED,
     // Plugin instance has been marked essential.
     THROTTLER_STATE_MARKED_ESSENTIAL,
   };
 
   // Maximum number of frames to examine for a suitable keyframe. After that, we
   // simply suspend the plugin where it's at. Chosen arbitrarily.
   static const int kMaximumFramesToExamine;
 
+  void AudioThrottledFrameTimeout();
   void EngageThrottle();
 
   ThrottlerState state_;
 
   bool is_hidden_for_placeholder_;
 
   blink::WebPlugin* web_plugin_;
 
+  // Holds a reference to the last received frame. This doesn't actually copy
+  // the pixel data, but rather increments the reference count to the pixels.
+  SkBitmap last_received_frame_;
+
   // Number of consecutive interesting frames we've encountered.
   int consecutive_interesting_frames_;
 
   // Number of frames we've examined to find a keyframe.
   int frames_examined_;
 
+  // Video plugins with throttled audio often stop generating frames.
+  // This timer is so we don't wait forever for candidate poster frames.
+  bool audio_throttled_;
+  base::DelayTimer<PluginInstanceThrottlerImpl> audio_throttled_frame_timeout_;
+
   ObserverList<Observer> observer_list_;
 
   base::WeakPtrFactory<PluginInstanceThrottlerImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PluginInstanceThrottlerImpl);
 };
 }
 
 #endif  // CONTENT_RENDERER_PEPPER_PLUGIN_INSTANCE_THROTTLER_IMPL_H_