Plugin Power Saver: Fix a dangling WebViewPlugin.

components/plugins/renderer/loadable_plugin_placeholder.cc

Index: components/plugins/renderer/loadable_plugin_placeholder.cc
diff --git a/components/plugins/renderer/loadable_plugin_placeholder.cc b/components/plugins/renderer/loadable_plugin_placeholder.cc
index aa9a97fedcd6237d352ee8237d847c34112cc4b1..7d50eecaf8112ca14a78ce2bfefb8e6f5cabf90c 100644
--- a/components/plugins/renderer/loadable_plugin_placeholder.cc
+++ b/components/plugins/renderer/loadable_plugin_placeholder.cc
@@ -104,9 +104,6 @@ void LoadablePluginPlaceholder::ReplacePlugin(blink::WebPlugin* new_plugin) {
   }
 
   container->setPlugin(new_plugin);
-  // Save the element in case the plugin is removed from the page during
-  // initialization.
-  blink::WebElement element = container->element();
   bool plugin_needs_initialization =
       !premade_throttler_ || new_plugin != premade_throttler_->GetWebPlugin();
   if (plugin_needs_initialization && !new_plugin->initialize(container)) {
@@ -115,17 +112,14 @@ void LoadablePluginPlaceholder::ReplacePlugin(blink::WebPlugin* new_plugin) {
       // still exists, restore the placeholder and destroy the new plugin.
       container->setPlugin(plugin());
       new_plugin->destroy();
+    } else {
+      // The container has been destroyed, along with the new plugin. Destroy
+      // our placeholder plugin also.
+      plugin()->destroy();
     }
     return;
   }
 
-  // The plugin has been removed from the page. Destroy the old plugin. We
-  // will be destroyed as soon as V8 garbage collects us.
-  if (!element.pluginContainer()) {
-    plugin()->destroy();
-    return;
-  }
-
   // During initialization, the new plugin might have replaced itself in turn
   // with another plugin. Make sure not to use the passed in |new_plugin| after
   // this point.