Plugins: Remove obsolete check in PepperWebPluginImpl.

content/renderer/pepper/pepper_webplugin_impl.h

 // 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.
 
 #ifndef CONTENT_RENDERER_PEPPER_PEPPER_WEBPLUGIN_IMPL_H_
 #define CONTENT_RENDERER_PEPPER_PEPPER_WEBPLUGIN_IMPL_H_
 
 #include <memory>
 #include <string>
 #include <vector>
@@ skipping 82 matching lines @@
       init_data_;  // Cleared upon successful initialization.
   // True if the instance represents the entire document in a frame instead of
   // being an embedded resource.
   bool full_frame_;
   std::unique_ptr<PluginInstanceThrottlerImpl> throttler_;
   scoped_refptr<PepperPluginInstanceImpl> instance_;
   gfx::Rect plugin_rect_;
   PP_Var instance_object_;
   blink::WebPluginContainer* container_;
 
-  // TODO(tommycli): Remove once we fix https://crbug.com/588624.
-  bool destroyed_;
-
   DISALLOW_COPY_AND_ASSIGN(PepperWebPluginImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_PEPPER_PEPPER_WEBPLUGIN_IMPL_H_