Making callbacks in Android ChildProcessLauncher generic.

content/public/android/java/src/org/chromium/content/common/IChildProcessService.aidl

 // Copyright 2012 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.
 
 package org.chromium.content.common;
 
-import org.chromium.content.common.IChildProcessCallback;
-
 import android.view.Surface;
 import android.os.Bundle;
 
 interface IChildProcessService {
   // On the first call to this method, the service will record the calling PID
   // and return true. Subsequent calls will only return true if the calling PID
   // is the same as the recorded one.
   boolean bindToCaller();
 
   // Sets up the initial IPC channel and returns the pid of the child process.
-  int setupConnection(in Bundle args, IChildProcessCallback callback);
+  int setupConnection(in Bundle args, IBinder callback);
 
   // Asks the child service to crash so that we can test the termination logic.
   void crashIntentionallyForTesting();
 }