Add support for CallbackPromiseAdapter<void, T> matching WebCallbacks<void, T>.

public/platform/WebGeofencingProvider.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 WebGeofencingProvider_h
 #define WebGeofencingProvider_h
 
 #include "public/platform/WebCallbacks.h"
 #include "public/platform/WebVector.h"
 
 namespace blink {
 
 struct WebGeofencingError;
 class WebGeofencingRegion;
 class WebString;
 
-typedef WebCallbacks<WebGeofencingError, WebGeofencingError> WebGeofencingCallbacks;
+typedef WebCallbacks<void, WebGeofencingError> WebGeofencingCallbacks;
 typedef WebCallbacks<WebVector<WebGeofencingRegion>, WebGeofencingError> WebGeofencingRegionsCallbacks;
 
 class WebGeofencingProvider {
 public:
     virtual ~WebGeofencingProvider() { }
 
-    // Registers a region. The provider must always pass null to onSuccess.
+    // Registers a region.
     // Ownership of the WebGeofencingCallbacks is transferred to the client.
-    // FIXME: cleanup the callback type to not have a success type.
     virtual void registerRegion(const WebGeofencingRegion&, WebGeofencingCallbacks*) = 0;
 
-    // Unregisters a region. The provider must always pass null to onSuccess.
+    // Unregisters a region.
     // Ownership of the WebGeofencingCallbacks is transferred to the client.
-    // FIXME: cleanup the callback type to not have a success type.
     virtual void unregisterRegion(const WebString& regionId, WebGeofencingCallbacks*) = 0;
 
     // Returns all the currently registered regions.
     // Ownership of the WebGeofencingCallbacks is transferred to the client.
     virtual void getRegisteredRegions(WebGeofencingRegionsCallbacks*) = 0;
 };
 
 } // namespace blink
 
 #endif // WebGeofencingProvider_h