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

webkit/plugins/ppapi/ppapi_webplugin_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "webkit/plugins/ppapi/ppapi_webplugin_impl.h"
 
 #include <cmath>
 
 #include "base/debug/crash_logging.h"
 #include "base/message_loop.h"
@@ skipping 102 matching lines @@
     return true;
   }
 
   init_data_.reset();
   container_ = container;
   return true;
 }
 
 void WebPluginImpl::destroy() {
   // Tell |container_| to clear references to this plugin's script objects.
-  container_->clearScriptObjects();
+  if (container_)
+    container_->clearScriptObjects();
 
   if (instance_) {
     ::ppapi::PpapiGlobals::Get()->GetVarTracker()->ReleaseVar(instance_object_);
     instance_object_ = PP_MakeUndefined();
     instance_->Delete();
     instance_ = NULL;
   }
 
   base::MessageLoop::current()->DeleteSoon(FROM_HERE, this);
 }
@@ skipping 161 matching lines @@
 void WebPluginImpl::rotateView(RotationType type) {
   instance_->RotateView(type);
 }
 
 bool WebPluginImpl::isPlaceholder() {
   return false;
 }
 
 }  // namespace ppapi
 }  // namespace webkit