Disable synchronous XMLHttpRequests in platform app documents.

chrome/test/data/extensions/platform_apps/restrictions/test.js

Index: chrome/test/data/extensions/platform_apps/restrictions/test.js
diff --git a/chrome/test/data/extensions/platform_apps/restrictions/test.js b/chrome/test/data/extensions/platform_apps/restrictions/test.js
index 25008d6f41bf21483569cf84858648e9afe3a8bd..25b45f9646e17826ece0c8b0a33203de8c417df5 100644
--- a/chrome/test/data/extensions/platform_apps/restrictions/test.js
+++ b/chrome/test/data/extensions/platform_apps/restrictions/test.js
@@ -6,14 +6,14 @@ var assertEq = chrome.test.assertEq;
 var fail = chrome.test.fail;
 var succeed = chrome.test.succeed;
 
-var error = "Not available for platform apps.";
+var DEFAULT_EXPECTED_ERROR = "Not available for platform apps.";
 
-function assertThrowsError(method) {
+function assertThrowsError(method, opt_expectedError) {
   try {
     method();
     fail("error not thrown");
   } catch (e) {
-    assertEq(e, error);
+    assertEq(e.message || e, opt_expectedError || DEFAULT_EXPECTED_ERROR);
   }
 }
 
@@ -113,5 +113,13 @@ chrome.test.runTests([
       });
     }
     succeed();
+  },
+
+  function testSyncXhr() {
+    var xhr = new XMLHttpRequest();
+    assertThrowsError(function() {
+      xhr.open('GET', 'data:should not load', false);
+    }, 'INVALID_ACCESS_ERR: DOM Exception 15');
+    succeed();
   }
 ]);