Only clear script objects during PPAPI WebPluginImpl teardown if it was initialized.

BUG=244572,152006

Review URL: https://chromiumcodereview.appspot.com/16023019

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@202747 0039d316-1c4b-4281-b951-d872f2087c98

webkit/plugins/ppapi/ppapi_webplugin_impl.cc

@@ -120,6 +120,7 @@ bool WebPluginImpl::initialize(WebPluginContainer* container) {
 
 void WebPluginImpl::destroy() {
   // Tell |container_| to clear references to this plugin's script objects.
+  if (container_)
     container_->clearScriptObjects();
 
   if (instance_) {