Remove unnecessary 'virtual' annotation from mojo

mojo/services/html_viewer/webclipboard_impl.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 MOJO_SERVICES_HTML_VIEWER_WEBCLIPBOARD_IMPL_H_
 #define MOJO_SERVICES_HTML_VIEWER_WEBCLIPBOARD_IMPL_H_
 
 #include "third_party/WebKit/public/platform/WebClipboard.h"
 #include "third_party/mojo_services/src/clipboard/public/interfaces/clipboard.mojom.h"
 
 namespace html_viewer {
 
 class WebClipboardImpl : public blink::WebClipboard {
  public:
   WebClipboardImpl(mojo::ClipboardPtr clipboard);
   virtual ~WebClipboardImpl();
 
   // blink::WebClipboard methods:
-  virtual uint64_t sequenceNumber(Buffer);
-  virtual bool isFormatAvailable(Format, Buffer);
-  virtual blink::WebVector<blink::WebString> readAvailableTypes(
+  uint64_t sequenceNumber(Buffer) override;
+  bool isFormatAvailable(Format, Buffer) override;
+  blink::WebVector<blink::WebString> readAvailableTypes(
       Buffer,
-      bool* containsFilenames);
-  virtual blink::WebString readPlainText(Buffer);
-  virtual blink::WebString readHTML(Buffer buffer,
-                                    blink::WebURL* pageURL,
-                                    unsigned* fragmentStart,
-                                    unsigned* fragmentEnd);
+      bool* containsFilenames) override;
+  blink::WebString readPlainText(Buffer) override;
+  blink::WebString readHTML(Buffer buffer,
+                            blink::WebURL* pageURL,
+                            unsigned* fragmentStart,
+                            unsigned* fragmentEnd) override;
   // TODO(erg): readImage()
-  virtual blink::WebString readCustomData(Buffer, const blink::WebString& type);
-  virtual void writePlainText(const blink::WebString&);
-  virtual void writeHTML(const blink::WebString& htmlText,
-                         const blink::WebURL&,
-                         const blink::WebString& plainText,
-                         bool writeSmartPaste);
+  blink::WebString readCustomData(Buffer,
+                                  const blink::WebString& type) override;
+  void writePlainText(const blink::WebString&) override;
+  void writeHTML(const blink::WebString& htmlText,
+                 const blink::WebURL&,
+                 const blink::WebString& plainText,
+                 bool writeSmartPaste) override;
 
  private:
   // Changes webkit buffers to mojo Clipboard::Types.
   mojo::Clipboard::Type ConvertBufferType(Buffer buffer);
 
   mojo::ClipboardPtr clipboard_;
 
   DISALLOW_COPY_AND_ASSIGN(WebClipboardImpl);
 };
 
 }  // namespace html_viewer
 
 #endif  // MOJO_SERVICES_HTML_VIEWER_WEBCLIPBOARD_IMPL_H_