Plugin Power Saver Tiny: Add Unthrottle by Omnibox bucket to histogram.

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 541427f23b8f1d307cda11b87f944fb82b15c2ab..ca981c6a33e7576b788a1496b80fe7f02da36d06 100644
--- a/content/public/renderer/plugin_instance_throttler.h
+++ b/content/public/renderer/plugin_instance_throttler.h
@@ -54,6 +54,7 @@ class CONTENT_EXPORT PluginInstanceThrottler {
     UNTHROTTLE_METHOD_BY_WHITELIST = 2,
     UNTHROTTLE_METHOD_BY_AUDIO = 3,
     UNTHROTTLE_METHOD_BY_SIZE_CHANGE = 4,
+    UNTHROTTLE_METHOD_BY_OMNIBOX_ICON = 5,
     UNTHROTTLE_METHOD_NUM_ITEMS
   };