Bug 1200426 - Convert PROCESS_OBJECT GeckoEvent to native call; r=snorp

The PROCESS_OBJECT GeckoEvent is used to set the layer client object in
Gecko once Gecko is done loading. This patch converts it to a native
call in GeckoView.Window.

widget/android/nsAppShell.cpp

@@ -434,17 +434,6 @@ nsAppShell::LegacyGeckoEvent::Run()
       }
       break;
 
-    case AndroidGeckoEvent::PROCESS_OBJECT: {
-
-      switch (curEvent->Action()) {
-      case AndroidGeckoEvent::ACTION_OBJECT_LAYER_CLIENT:
-        AndroidBridge::Bridge()->SetLayerClient(
-                widget::GeckoLayerClient::Ref::From(curEvent->Object().wrappedObject()));
-        break;
-      }
-      break;
-    }
-
     case AndroidGeckoEvent::LOCATION_EVENT: {
         if (!gLocationCallback)
             break;