Plugin Power Saver: Mute throttled plugins.

content/public/renderer/plugin_instance_throttler.h

Index: content/public/renderer/plugin_instance_throttler.h
diff --git a/content/public/renderer/plugin_instance_throttler.h b/content/public/renderer/plugin_instance_throttler.h
index 5fa327679794a658b62c58f191c39f24a236f664..ab9ad14d10e5584a8e09eb75634dbff20bbb9cc6 100644
--- a/content/public/renderer/plugin_instance_throttler.h
+++ b/content/public/renderer/plugin_instance_throttler.h
@@ -59,9 +59,22 @@ class CONTENT_EXPORT PluginInstanceThrottler {
     UNTHROTTLE_METHOD_NUM_ITEMS
   };
 
+  enum PowerSaverState {
+    // Initial state if Power Saver is disabled. We are just collecting metrics.
+    POWER_SAVER_DISABLED,
+    // Initial state if Power Saver is enabled. Waiting for a keyframe.
+    POWER_SAVER_ENABLED_AWAITING_KEYFRAME,
+    // We've chosen a keyframe and the plug-in is throttled.
+    POWER_SAVER_ENABLED_PLUGIN_THROTTLED,
+    // Plugin instance is no longer considered peripheral. This can happen from
+    // a user click, whitelisting, or some other reason. We can end up in this
+    // state regardless of whether power saver is enabled.
+    POWER_SAVER_MARKED_ESSENTIAL
+  };
+
   class Observer {
    public:
-    virtual void OnThrottleStateChange() = 0;
+    virtual void OnPowerSaverStateChange(PowerSaverState state) = 0;
   };
 
   // Returns a nullptr if no throttler needed based on |power_saver_mode|.