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

ppapi/proxy/file_system_resource.h

 // Copyright (c) 2013 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_SYSTEM_RESOURCE_H_
 #define PPAPI_PROXY_FILE_SYSTEM_RESOURCE_H_
 
 #include <map>
 #include <queue>
 #include <string>
@@ skipping 24 matching lines @@
                      PP_Instance instance,
                      PP_FileSystemType type);
   // Creates a FileSystemResource, attached to an existing pending host
   // resource. The |pending_renderer_id| and |pending_browser_id| must be
   // already-opened file systems.
   FileSystemResource(Connection connection,
                      PP_Instance instance,
                      int pending_renderer_id,
                      int pending_browser_id,
                      PP_FileSystemType type);
-  virtual ~FileSystemResource();
+  ~FileSystemResource() override;
 
   // Resource overrides.
-  virtual thunk::PPB_FileSystem_API* AsPPB_FileSystem_API() override;
+  thunk::PPB_FileSystem_API* AsPPB_FileSystem_API() override;
 
   // PPB_FileSystem_API implementation.
-  virtual int32_t Open(int64_t expected_size,
-                       scoped_refptr<TrackedCallback> callback) override;
-  virtual PP_FileSystemType GetType() override;
-  virtual void OpenQuotaFile(PP_Resource file_io) override;
-  virtual void CloseQuotaFile(PP_Resource file_io) override;
+  int32_t Open(int64_t expected_size,
+               scoped_refptr<TrackedCallback> callback) override;
+  PP_FileSystemType GetType() override;
+  void OpenQuotaFile(PP_Resource file_io) override;
+  void CloseQuotaFile(PP_Resource file_io) override;
   typedef base::Callback<void(int64_t)> RequestQuotaCallback;
-  virtual int64_t RequestQuota(int64_t amount,
-                               const RequestQuotaCallback& callback) override;
+  int64_t RequestQuota(int64_t amount,
+                       const RequestQuotaCallback& callback) override;
 
   int32_t InitIsolatedFileSystem(const std::string& fsid,
                                  PP_IsolatedFileSystemType_Private type,
                                  const base::Callback<void(int32_t)>& callback);
  private:
   struct QuotaRequest {
     QuotaRequest(int64_t amount,
                  const RequestQuotaCallback& callback);
     ~QuotaRequest();
 
@@ skipping 26 matching lines @@
   int64_t reserved_quota_;
   bool reserving_quota_;
 
   DISALLOW_COPY_AND_ASSIGN(FileSystemResource);
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_FILE_SYSTEM_RESOURCE_H_