Standardize usage of virtual/override/final in extensions/

extensions/browser/blob_holder.h

 // Copyright 2014 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 EXTENSIONS_BROWSER_BLOB_HOLDER_H_
 #define EXTENSIONS_BROWSER_BLOB_HOLDER_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 12 matching lines @@
 class ExtensionMessageFilter;
 
 // Used for holding onto Blobs created into the browser process until a
 // renderer takes over ownership. This class operates on the UI thread.
 class BlobHolder : public base::SupportsUserData::Data {
  public:
   // Will create the BlobHolder if it doesn't already exist.
   static BlobHolder* FromRenderProcessHost(
       content::RenderProcessHost* render_process_host);
 
-  virtual ~BlobHolder();
+  ~BlobHolder() override;
 
   // Causes BlobHolder to take ownership of |blob|.
   void HoldBlobReference(scoped_ptr<content::BlobHandle> blob);
 
  private:
   typedef std::multimap<std::string, linked_ptr<content::BlobHandle> >
       BlobHandleMultimap;
 
   explicit BlobHolder(content::RenderProcessHost* render_process_host);
 
   // BlobHolder will drop a blob handle for each element in blob_uuids.
   // If caller wishes to drop multiple references to the same blob,
   // |blob_uuids| may contain duplicate UUIDs.
   void DropBlobs(const std::vector<std::string>& blob_uuids);
   friend class ExtensionMessageFilter;
 
   bool ContainsBlobHandle(content::BlobHandle* handle) const;
 
   // A reference to the owner of this class.
   content::RenderProcessHost* render_process_host_;
 
   BlobHandleMultimap held_blobs_;
 
   DISALLOW_COPY_AND_ASSIGN(BlobHolder);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_BLOB_HOLDER_H_