DevTools: simplify JSONValues API, prepare to the OwnPtr migration.

third_party/WebKit/Source/platform/v8_inspector/RemoteObjectId.cpp

 // Copyright 2015 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 "platform/v8_inspector/RemoteObjectId.h"
 
 #include "platform/JSONParser.h"
 #include "platform/JSONValues.h"
 #include "wtf/PassOwnPtr.h"
 #include "wtf/RefPtr.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 RemoteObjectIdBase::RemoteObjectIdBase() : m_injectedScriptId(0) { }
 
 PassRefPtr<JSONObject> RemoteObjectIdBase::parseInjectedScriptId(const String& objectId)
 {
     RefPtr<JSONValue> parsedValue = parseJSON(objectId);
     if (!parsedValue || parsedValue->type() != JSONValue::TypeObject)
         return nullptr;
 
-    RefPtr<JSONObject> parsedObjectId = parsedValue->asObject();
+    RefPtr<JSONObject> parsedObjectId = JSONObject::cast(parsedValue.release());
     bool success = parsedObjectId->getNumber("injectedScriptId", &m_injectedScriptId);
     if (success)
         return parsedObjectId.release();
     return nullptr;
 }
 
 RemoteObjectId::RemoteObjectId() : RemoteObjectIdBase(), m_id(0) { }
 
 PassOwnPtr<RemoteObjectId> RemoteObjectId::parse(const String& objectId)
 {
@@ skipping 21 matching lines @@
     if (!success)
         return nullptr;
 
     RefPtr<JSONValue> value = parsedObjectId->get("asyncOrdinal");
     if (value &&!value->asNumber(&result->m_asyncStackOrdinal))
         return nullptr;
     return result.release();
 }
 
 } // namespace blink