Remove onUpdate from systemInfo.cpu API

chrome/common/extensions/api/system_info_cpu.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.
 
 // File-level comment to appease parser. Eventually this will not be necessary.
 namespace systemInfo.cpu {
 
   dictionary CpuInfo {
     // The number of logical processors.
     long numOfProcessors;
     // The architecture name of the processors.
     DOMString archName;
     // The model name of the processors.
     DOMString modelName;
   };
 
-  dictionary CpuUpdateInfo {
-    // The average usage percent of all processors, as a number 
-    // between 0 and 100.
-    double averageUsage;
-    // The CPU usage array for each logic processor.
-    double[] usagePerProcessor;
-  };
-
   callback CpuInfoCallback = void (CpuInfo info);
   
   interface Functions {
     // Queries basic CPU information of the system.
     static void get(CpuInfoCallback callback);
   };
-
-  interface Events {
-    // Fired periodically to report CPU history usage information. The default
-    // period interval is 1 seconds.
-    static void onUpdated(CpuUpdateInfo info);
-  };
 };