Credential manager: Convert strings to URLs early.

Source/platform/credentialmanager/PlatformLocalCredential.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 PlatformLocalCredential_h
 #define PlatformLocalCredential_h
 
 #include "platform/credentialmanager/PlatformCredential.h"
 #include "platform/heap/Handle.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 class PLATFORM_EXPORT PlatformLocalCredential FINAL : public PlatformCredential {
     WTF_MAKE_NONCOPYABLE(PlatformLocalCredential);
 public:
-    static PlatformLocalCredential* create(const String& id, const String& name, const String& avatarURL, const String& password);
+    static PlatformLocalCredential* create(const String& id, const String& name, const KURL& avatarURL, const String& password);
     virtual ~PlatformLocalCredential();
 
     const String& password() const { return m_password; }
 
 private:
-    PlatformLocalCredential(const String& id, const String& name, const String& avatarURL, const String& password);
+    PlatformLocalCredential(const String& id, const String& name, const KURL& avatarURL, const String& password);
 
     String m_password;
 };
 
 } // namespace blink
 
 #endif // PlatformLocalCredential_h