Short-circuit failures in BLE js tests

chrome/test/data/extensions/api_test/bluetooth_low_energy/read_descriptor_value/runtest.js

Index: chrome/test/data/extensions/api_test/bluetooth_low_energy/read_descriptor_value/runtest.js
diff --git a/chrome/test/data/extensions/api_test/bluetooth_low_energy/read_descriptor_value/runtest.js b/chrome/test/data/extensions/api_test/bluetooth_low_energy/read_descriptor_value/runtest.js
index e7693a96ae9fdf73eba67784d0d48c62f885a8fd..550052023a478531e5fd54ba4e4093bf3539a53c 100644
--- a/chrome/test/data/extensions/api_test/bluetooth_low_energy/read_descriptor_value/runtest.js
+++ b/chrome/test/data/extensions/api_test/bluetooth_low_energy/read_descriptor_value/runtest.js
@@ -2,7 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+var error;
+
 function testReadDescriptorValue() {
+  if (error !== undefined) {
+    chrome.test.sendMessage('fail');
+    chrome.test.fail(error);
+  }
   chrome.test.assertTrue(descriptor != null, '\'descriptor\' is null');
   chrome.test.assertEq(descId, descriptor.instanceId);
 
@@ -15,22 +21,30 @@ var badDescId = 'desc_id1';
 
 var descriptor = null;
 
+function earlyError(message) {
+  error = message;
+  chrome.test.runTests([testReadDescriptorValue]);
+}
+
 // 1. Unknown descriptor instanceId.
 readDescriptorValue(badDescId, function (result) {
   if (result || !chrome.runtime.lastError) {
-    chrome.test.fail('\'badDescId\' did not cause failure');
+    earlyError('\'badDescId\' did not cause failure');
+    return;
   }
 
   // 2. Known descriptor instanceId, but call failure.
   readDescriptorValue(descId, function (result) {
     if (result || !chrome.runtime.lastError) {
-      chrome.test.fail('readDescriptorValue should have failed');
+      earlyError('readDescriptorValue should have failed');
+      return;
     }
 
     // 3. Call should succeed.
     readDescriptorValue(descId, function (result) {
       if (chrome.runtime.lastError) {
-        chrome.test.fail(chrome.runtime.lastError.message);
+        earlyError(chrome.runtime.lastError.message);
+        return;
       }
 
       descriptor = result;