Move chrome.diagnostics API to extensions/.

extensions/common/api/diagnostics.idl

 // Copyright 2013 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.
 
 // Use the <code>chrome.diagnostics</code> API to query various properties of
 // the environment that may be useful for diagnostics.
 namespace diagnostics {
   dictionary SendPacketOptions {
     // Target IP address.
     DOMString ip;
@@ skipping 17 matching lines @@
   };
 
   callback SendPacketCallback = void(SendPacketResult result);
 
   interface Functions {
     // Send a packet of the given type with the given parameters.
     static void sendPacket(SendPacketOptions options,
                            SendPacketCallback callback);
   };
 };