Add a generic template for system info provider

chrome/test/data/extensions/api_test/systeminfo/cpu/test_cpuinfo_api.js

 // Copyright (c) 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.
 
 // systeminfo.cpu api test
 // browser_tests.exe --gtest_filter=SystemInfoCpuApiTest.*
 
 chrome.systemInfo = chrome.experimental.systemInfo;
 
 chrome.test.runTests([
   function testGet() {
-    chrome.systemInfo.cpu.get(chrome.test.callbackPass(function(result){
-      chrome.test.assertTrue(result.cores.length == 1);
-      var core = result.cores[0];
-      chrome.test.assertTrue(core.load == 53);
-    }));
+    for(var i = 0; i < 20; ++i) {
+      chrome.systemInfo.cpu.get(chrome.test.callbackPass(function(result) {
+        chrome.test.assertTrue(result.cores.length == 4);
+        var core;
+        for (var i = 0; i < result.cores.length; ++i) {
+          core = result.cores[i];
+          chrome.test.assertTrue(core.load == i*10);
+        }
+      }));
+    }
   },
 ]);