Plugin Power Saver: Add UI Overlay to throttled plugin using placeholder.

content/renderer/pepper/plugin_instance_throttler_impl.h

Index: content/renderer/pepper/plugin_instance_throttler_impl.h
diff --git a/content/renderer/pepper/plugin_instance_throttler_impl.h b/content/renderer/pepper/plugin_instance_throttler_impl.h
index 14352c119b204e5b736ef010e86d6c1ef3c3a68a..c8cbb8bb9eb535fb92ab859e54b4bf6a9d59a54d 100644
--- a/content/renderer/pepper/plugin_instance_throttler_impl.h
+++ b/content/renderer/pepper/plugin_instance_throttler_impl.h
@@ -34,7 +34,9 @@ class CONTENT_EXPORT PluginInstanceThrottlerImpl
   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;
 
   bool needs_representative_keyframe() const {
     return state_ == POWER_SAVER_ENABLED_AWAITING_KEYFRAME;
@@ -70,11 +72,18 @@ class CONTENT_EXPORT PluginInstanceThrottlerImpl
 
   void EngageThrottle();
 
+  void TimeoutKeyframeExtraction();
+
   State state_;
 
+  bool is_hidden_for_placeholder_;
+
   // Number of consecutive interesting frames we've encountered.
   int consecutive_interesting_frames_;
 
+  // If true, take the next frame as the keyframe regardless of interestingness.
+  bool keyframe_extraction_timed_out_;
+
   ObserverList<Observer> observer_list_;
 
   base::WeakPtrFactory<PluginInstanceThrottlerImpl> weak_factory_;