Plugin Power Saver: Fix race between GIN bindings and destruction

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 5c804c9e4c8dc618495a21fcd0e604466ceda5a6..1f38fdbf87d685db9ef62e9ef21a33c1bc0b1be1 100644
--- a/components/plugins/renderer/loadable_plugin_placeholder.cc
+++ b/components/plugins/renderer/loadable_plugin_placeholder.cc
@@ -330,6 +330,9 @@ void LoadablePluginPlaceholder::DidFinishLoadingCallback() {
 }
 
 void LoadablePluginPlaceholder::DidFinishIconRepositionForTestingCallback() {
+  if (!plugin())
+    return;
+
   // Set an attribute and post an event, so browser tests can wait for the
   // placeholder to be ready to receive simulated user input.
   blink::WebElement element = plugin()->container()->element();