Update {virtual,override} to follow C++11 style in ppapi.

ppapi/proxy/file_chooser_resource.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 PPAPI_PROXY_FILE_CHOOSER_RESOURCE_H_
 #define PPAPI_PROXY_FILE_CHOOSER_RESOURCE_H_
 
 #include <queue>
 #include <string>
 #include <vector>
@@ skipping 11 matching lines @@
 namespace proxy {
 
 class PPAPI_PROXY_EXPORT FileChooserResource
     : public PluginResource,
       public NON_EXPORTED_BASE(thunk::PPB_FileChooser_API) {
  public:
   FileChooserResource(Connection connection,
                       PP_Instance instance,
                       PP_FileChooserMode_Dev mode,
                       const std::string& accept_types);
-  virtual ~FileChooserResource();
+  ~FileChooserResource() override;
 
   // Resource overrides.
-  virtual thunk::PPB_FileChooser_API* AsPPB_FileChooser_API() override;
+  thunk::PPB_FileChooser_API* AsPPB_FileChooser_API() override;
 
   // PPB_FileChooser_API.
-  virtual int32_t Show(const PP_ArrayOutput& output,
-                       scoped_refptr<TrackedCallback> callback) override;
-  virtual int32_t ShowWithoutUserGesture(
+  int32_t Show(const PP_ArrayOutput& output,
+               scoped_refptr<TrackedCallback> callback) override;
+  int32_t ShowWithoutUserGesture(
       PP_Bool save_as,
       PP_Var suggested_file_name,
       const PP_ArrayOutput& output,
       scoped_refptr<TrackedCallback> callback) override;
-  virtual int32_t Show0_5(scoped_refptr<TrackedCallback> callback) override;
-  virtual PP_Resource GetNextChosenFile() override;
-  virtual int32_t ShowWithoutUserGesture0_5(
+  int32_t Show0_5(scoped_refptr<TrackedCallback> callback) override;
+  PP_Resource GetNextChosenFile() override;
+  int32_t ShowWithoutUserGesture0_5(
       PP_Bool save_as,
       PP_Var suggested_file_name,
       scoped_refptr<TrackedCallback> callback) override;
 
   // Parses the accept string into the given vector.
   static void PopulateAcceptTypes(const std::string& input,
                                   std::vector<std::string>* output);
 
  private:
   void OnPluginMsgShowReply(
@@ skipping 18 matching lines @@
 
   scoped_refptr<TrackedCallback> callback_;
 
   DISALLOW_COPY_AND_ASSIGN(FileChooserResource);
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_FILE_CHOOSER_RESOURCE_H_