Use WebIDBKeyPath type in WebKit API, implement IndexedDBKeyPath type.

content/common/indexed_db/proxy_webidbindex_impl.cc

 // Copyright (c) 2012 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 "content/common/indexed_db/proxy_webidbindex_impl.h"
 
 #include "content/common/indexed_db/indexed_db_dispatcher.h"
 #include "content/common/indexed_db/indexed_db_messages.h"
 #include "content/common/indexed_db/proxy_webidbtransaction_impl.h"
 #include "content/common/child_thread.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebIDBKeyPath.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebString.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebVector.h"
 
 using WebKit::WebExceptionCode;
 using WebKit::WebDOMStringList;
+using WebKit::WebIDBKeyPath;
 using WebKit::WebString;
 using WebKit::WebVector;
 
 RendererWebIDBIndexImpl::RendererWebIDBIndexImpl(int32 idb_index_id)
     : idb_index_id_(idb_index_id) {
 }
 
 RendererWebIDBIndexImpl::~RendererWebIDBIndexImpl() {
   // It's not possible for there to be pending callbacks that address this
   // object since inside WebKit, they hold a reference to the object wich owns
@@ skipping 10 matching lines @@
   return result;
 }
 
 WebString RendererWebIDBIndexImpl::storeName() const {
   string16 result;
   IndexedDBDispatcher::Send(
       new IndexedDBHostMsg_IndexStoreName(idb_index_id_, &result));
   return result;
 }
 
-WebString RendererWebIDBIndexImpl::keyPathString() const {
-  NullableString16 result;
+WebIDBKeyPath RendererWebIDBIndexImpl::keyPath() const {
+  content::IndexedDBKeyPath result;
   IndexedDBDispatcher::Send(
       new IndexedDBHostMsg_IndexKeyPath(idb_index_id_, &result));
   return result;
 }
 
 bool RendererWebIDBIndexImpl::unique() const {
   bool result;
   IndexedDBDispatcher::Send(
       new IndexedDBHostMsg_IndexUnique(idb_index_id_, &result));
   return result;
@@ skipping 55 matching lines @@
 void RendererWebIDBIndexImpl::getKey(
     const WebKit::WebIDBKeyRange& key_range,
     WebKit::WebIDBCallbacks* callbacks,
     const WebKit::WebIDBTransaction& transaction,
     WebExceptionCode& ec) {
   IndexedDBDispatcher* dispatcher =
       IndexedDBDispatcher::ThreadSpecificInstance();
   dispatcher->RequestIDBIndexGetKey(
       IndexedDBKeyRange(key_range), callbacks, idb_index_id_, transaction, &ec);
 }