Coverity: Fix missing const on RendererWebIDBIndexImpl overridden methods.

chrome/renderer/renderer_webidbdatabase_impl.h

 // Copyright (c) 2010 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 CHROME_RENDERER_RENDERER_WEBIDBDATABASE_IMPL_H_
 #define CHROME_RENDERER_RENDERER_WEBIDBDATABASE_IMPL_H_
 
 #include "base/basictypes.h"
 #include "third_party/WebKit/WebKit/chromium/public/WebIDBCallbacks.h"
 #include "third_party/WebKit/WebKit/chromium/public/WebIDBDatabase.h"
 
 namespace WebKit {
 class WebFrame;
 class WebIDBCallbacks;
 class WebString;
 }
 
 class RendererWebIDBDatabaseImpl : public WebKit::WebIDBDatabase {
  public:
   explicit RendererWebIDBDatabaseImpl(int32 idb_database_id);
   virtual ~RendererWebIDBDatabaseImpl();
 
   // WebKit::WebIDBDatabase
-  virtual WebKit::WebString name();
-  virtual WebKit::WebString description();
-  virtual WebKit::WebString version();
-  virtual WebKit::WebDOMStringList objectStores();
+  virtual WebKit::WebString name() const;
+  virtual WebKit::WebString description() const;
+  virtual WebKit::WebString version() const;
+  virtual WebKit::WebDOMStringList objectStores() const;
   virtual void createObjectStore(
       const WebKit::WebString& name, const WebKit::WebString& key_path,
       bool auto_increment, WebKit::WebIDBCallbacks* callbacks);
 
  private:
   int32 idb_database_id_;
 };
 
 #endif  // CHROME_RENDERER_RENDERER_WEBIDBDATABASE_IMPL_H_