Coverity: Fix missing const on RendererWebIDBIndexImpl overridden methods.

chrome/renderer/renderer_webidbindex_impl.cc

 // 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.
 
 #include "chrome/renderer/renderer_webidbindex_impl.h"
 
 #include "chrome/common/render_messages.h"
 #include "chrome/renderer/render_thread.h"
 #include "chrome/renderer/indexed_db_dispatcher.h"
 
 using WebKit::WebDOMStringList;
 using WebKit::WebString;
 using WebKit::WebVector;
 
 RendererWebIDBIndexImpl::RendererWebIDBIndexImpl(int32 idb_index_id)
     : idb_index_id_(idb_index_id) {
 }
 
 RendererWebIDBIndexImpl::~RendererWebIDBIndexImpl() {
   // TODO(jorlow): Is it possible for this to be destroyed but still have
   //               pending callbacks?  If so, fix!
   RenderThread::current()->Send(new ViewHostMsg_IDBIndexDestroyed(
       idb_index_id_));
 }
 
-WebString RendererWebIDBIndexImpl::name() {
+WebString RendererWebIDBIndexImpl::name() const {
   string16 result;
   RenderThread::current()->Send(
       new ViewHostMsg_IDBIndexName(idb_index_id_, &result));
   return result;
 }
 
-WebString RendererWebIDBIndexImpl::keyPath() {
+WebString RendererWebIDBIndexImpl::keyPath() const {
   NullableString16 result;
   RenderThread::current()->Send(
       new ViewHostMsg_IDBIndexKeyPath(idb_index_id_, &result));
   return result;
 }
 
-bool RendererWebIDBIndexImpl::unique() {
+bool RendererWebIDBIndexImpl::unique() const {
   bool result;
   RenderThread::current()->Send(
       new ViewHostMsg_IDBIndexUnique(idb_index_id_, &result));
   return result;
 }