Change the web store private install API to accept a localized extension name.

chrome/test/data/extensions/api_test/webstore_private/common.js

 // Copyright (c) 2011 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.
 
 // The id of the extension we're using for install tests.
 var extensionId = "enfkhcelefdadlmkffamgdlgplcionje";
 
 var assertEq = chrome.test.assertEq;
 var assertNoLastError = chrome.test.assertNoLastError;
 var callbackFail = chrome.test.callbackFail;
@@ skipping 31 matching lines @@
     // Strip the data url prefix to just get the base64-encoded bytes.
     cachedIcon = tmp.slice(tmp.search(",")+1);
     callback(cachedIcon);
   };
   img.src = "extension/icon.png";
 }
 
 var cachedManifest = null;
 
 // This returns the string contents of the extension's manifest file.
-function getManifest() {
+function getManifest(alternativePath) {
   if (cachedManifest)
     return cachedManifest;
 
   // Do a synchronous XHR to get the manifest.
   var xhr = new XMLHttpRequest();
-  xhr.open("GET", "extension/manifest.json", false);
+  xhr.open("GET",
+           alternativePath ? alternativePath : "extension/manifest.json",
+           false);
   xhr.send(null);
   return xhr.responseText;
 }