[MediaRouter UI] Compile MR WebUI js code with Closure.

chrome/browser/resources/media_router/externs.js

Index: chrome/browser/resources/media_router/externs.js
diff --git a/ipc/ipc_handle_win.cc b/chrome/browser/resources/media_router/externs.js
similarity index 52%
copy from ipc/ipc_handle_win.cc
copy to chrome/browser/resources/media_router/externs.js
index da3b9bb6125dba3e65d0dcbf83902ee5248a5ffe..5821b32cbbb4f9227a6d816c4f6e7c57ec542a44 100644
--- a/ipc/ipc_handle_win.cc
+++ b/chrome/browser/resources/media_router/externs.js
@@ -2,14 +2,14 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "ipc/ipc_handle_win.h"
+/**
+ * @fileoverview Externs to be declared to properly compile JS code.
+ * @externs
+ */
 
-namespace IPC {
+var performance = {};
 
-HandleForTransit CreateHandleForTransit(HANDLE handle) {
-  HandleForTransit hft;
-  hft.handle = handle;
-  return hft;
-}
-
-}  // namespace IPC
+/**
+ * @return {number}
+ */
+performance.now = function() {};