Plugin Power Saver: Replace all "plug-in" with "plugin" for consistency.

components/plugins/renderer/loadable_plugin_placeholder.h

Index: components/plugins/renderer/loadable_plugin_placeholder.h
diff --git a/components/plugins/renderer/loadable_plugin_placeholder.h b/components/plugins/renderer/loadable_plugin_placeholder.h
index bc09b73fdf39ef6dfe7402d24d1e7f035cbf23ba..e67c86104537182898d1c84b85af0e75b5f07b05 100644
--- a/components/plugins/renderer/loadable_plugin_placeholder.h
+++ b/components/plugins/renderer/loadable_plugin_placeholder.h
@@ -11,7 +11,7 @@
 #include "content/public/renderer/plugin_instance_throttler.h"
 
 namespace plugins {
-// Placeholders can be used if a plug-in is missing or not available
+// Placeholders can be used if a plugin is missing or not available
 // (blocked or disabled).
 class LoadablePluginPlaceholder
     : public PluginPlaceholder,
@@ -30,7 +30,7 @@ class LoadablePluginPlaceholder
     power_saver_enabled_ = power_saver_enabled;
   }
 
-  // Defer loading of plug-in, and instead show the Power Saver poster image.
+  // Defer loading of plugin, and instead show the Power Saver poster image.
   void BlockForPowerSaverPoster();
 #endif