Use Promises for screen.lockOrientation().

public/platform/Platform.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 18 matching lines @@
  */
 
 #ifndef Platform_h
 #define Platform_h
 
 #ifdef WIN32
 #include <windows.h>
 #endif
 
 #include "WebAudioDevice.h"
+#include "WebCallbacks.h"
 #include "WebCommon.h"
+#include "WebDOMException.h"
 #include "WebData.h"
 #include "WebGamepadListener.h"
 #include "WebGamepads.h"
 #include "WebGraphicsContext3D.h"
 #include "WebLocalizedString.h"
 #include "WebScreenOrientationLockType.h"
+#include "WebScreenOrientationType.h"
 #include "WebSpeechSynthesizer.h"
 #include "WebStorageQuotaCallbacks.h"
 #include "WebStorageQuotaType.h"
 #include "WebString.h"
 #include "WebURLError.h"
 #include "WebVector.h"
 
 class GrContext;
 
 namespace blink {
@@ skipping 569 matching lines @@
     // If null, the platform stops providing device orientation data to the current listener.
     virtual void setDeviceOrientationListener(blink::WebDeviceOrientationListener*) { }
 
     // Sets a Listener to listen for device light data updates.
     // If null, the platform stops providing device light data to the current listener.
     virtual void setDeviceLightListener(blink::WebDeviceLightListener*) { }
 
 
     // Screen Orientation -------------------------------------------------
 
+    typedef WebCallbacks<blink::WebScreenOrientationType, blink::WebDOMException> WebLockOrientationCallback;
     virtual void setScreenOrientationListener(blink::WebScreenOrientationListener*) { }
     virtual void lockOrientation(WebScreenOrientationLockType) { }
+    // Request a screen orientation lock and pass a |callback| object to be used
+    // to notify of success/failure. The |callback| parameter is expected to be
+    // owned by the implementation.
+    virtual void lockOrientation(WebScreenOrientationLockType, WebLockOrientationCallback* callback)
+    {
+        delete callback; // prevents memory leak if there is no implementation.
+    }
     virtual void unlockOrientation() { }
 
 
     // Quota -----------------------------------------------------------
 
     // Queries the storage partition's storage usage and quota information.
     // WebStorageQuotaCallbacks::didQueryStorageUsageAndQuota will be called
     // with the current usage and quota information for the partition. When
     // an error occurs WebStorageQuotaCallbacks::didFail is called with an
     // error code.
     virtual void queryStorageUsageAndQuota(
         const WebURL& storagePartition,
         WebStorageQuotaType,
         WebStorageQuotaCallbacks) { }
 
 
     // WebDatabase --------------------------------------------------------
 
     virtual WebDatabaseObserver* databaseObserver() { return 0; }
 
 
 protected:
     virtual ~Platform() { }
 };
 
 } // namespace blink
 
 #endif