Ensure we check the page pointer before using it after we come out of NPP_Han...

webkit/glue/webplugin_impl.cc

 // Copyright (c) 2006-2008 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 "config.h"
 #include "webkit/glue/webplugin_impl.h"
 
 #include "Cursor.h"
 #include "Document.h"
 #include "DocumentLoader.h"
@@ skipping 845 matching lines @@
     return;
   }
 
   // TODO(pkasting): http://b/1119691 This conditional seems exactly backwards,
   // but it matches Safari's code, and if I reverse it, giving focus to a
   // transparent (windowless) plugin fails.
   WebCursor cursor;
   if (!delegate_->HandleEvent(&np_event, &cursor))
     event->setDefaultHandled();
 
+  WebCore::Page* page = parent_view->frame()->page();
+  if (!page)
+    return;
+
   ChromeClientImpl* chrome_client =
-      static_cast<ChromeClientImpl*>(
-          parent_view->frame()->page()->chrome()->client());
+      static_cast<ChromeClientImpl*>(page->chrome()->client());
 
   // A windowless plugin can change the cursor in response to the WM_MOUSEMOVE
   // event. We need to reflect the changed cursor in the frame view as the
   // mouse is moved in the boundaries of the windowless plugin.
   chrome_client->SetCursorForPlugin(cursor);
 
 #else
   NOTIMPLEMENTED();
 #endif
 }
@@ skipping 542 matching lines @@
     client_index = clients_.erase(client_index);
     if (resource_client)
       resource_client->DidFail();
   }
 
   // This needs to be called now and not in the destructor since the
   // webframe_ might not be valid anymore.
   webframe_->set_plugin_delegate(NULL);
   webframe_ = NULL;
 }