[Extensions] Re-enable a Storage API test.

The ExtensionSettingsApiTest.OnChangedNotificationsFromSyncCheck
was disabled for flakiness and became stale. This CL fixes the test
and cleans up the JavaScript code. The test passed 3000 iterations
on the bots.

Bug: 101110
Change-Id: Ia969ba620900382395d09ec28e8d8ea379c79d5d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2211079
Commit-Queue: David Bertoni <dbertoni@chromium.org>
Reviewed-by: Archana Simha <archanasimha@chromium.org>
Cr-Commit-Position: refs/heads/master@{#771884}

chrome/browser/extensions/api/storage/settings_apitest.cc

@@ -339,9 +339,8 @@ IN_PROC_BROWSER_TEST_F(ExtensionSettingsApiTest,
   EXPECT_TRUE(catcher_incognito.GetNextResult()) << catcher.message();
 }
 
-// Disabled, see crbug.com/101110
 IN_PROC_BROWSER_TEST_F(ExtensionSettingsApiTest,
-    DISABLED_OnChangedNotificationsFromSync) {
+                       OnChangedNotificationsFromSync) {
   // We need 2 ResultCatchers because we'll be running the same test in both
   // regular and incognito mode.
   ResultCatcher catcher, catcher_incognito;

chrome/test/data/extensions/api_test/settings/split_incognito/background.js

@@ -2,15 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-var api = chrome.storage;
-var assertEq = chrome.test.assertEq;
-var inIncognitoContext = chrome.extension.inIncognitoContext;
-
 ['sync', 'local'].forEach(function(namespace) {
-  api[namespace].notifications = {};
-  api.onChanged.addListener(function(changes, event_namespace) {
+  chrome.storage[namespace].notifications = {};
+  chrome.storage.onChanged.addListener(function(changes, event_namespace) {
     if (event_namespace == namespace) {
-      var notifications = api[namespace].notifications;
+      var notifications = chrome.storage[namespace].notifications;
       Object.keys(changes).forEach(function(key) {
         notifications[key] = changes[key];
       });
@@ -29,13 +25,13 @@ var testActions = {
   },
   assertEmpty: function(callback) {
     this.get(null, function(settings) {
-      assertEq({}, settings);
+      chrome.test.assertEq({}, settings);
       callback();
     });
   },
   assertFoo: function(callback) {
     this.get(null, function(settings) {
-      assertEq({foo: "bar"}, settings);
+      chrome.test.assertEq({foo: "bar"}, settings);
       callback();
     });
   },
@@ -49,7 +45,7 @@ var testActions = {
     this.clear(callback);
   },
   assertNoNotifications: function(callback) {
-    assertEq({}, this.notifications);
+    chrome.test.assertEq({}, this.notifications);
     callback();
   },
   clearNotifications: function(callback) {
@@ -57,11 +53,11 @@ var testActions = {
     callback();
   },
   assertAddFooNotification: function(callback) {
-    assertEq({ foo: { newValue: 'bar' } }, this.notifications);
+    chrome.test.assertEq({ foo: { newValue: 'bar' } }, this.notifications);
     callback();
   },
   assertDeleteFooNotification: function(callback) {
-    assertEq({ foo: { oldValue: 'bar' } }, this.notifications);
+    chrome.test.assertEq({ foo: { oldValue: 'bar' } }, this.notifications);
     callback();
   }
 };
@@ -70,15 +66,20 @@ var testActions = {
 // to stop (when the message has isFinalAction set to true).
 function testEverything() {
   function next() {
-    var waiting = inIncognitoContext ? "waiting_incognito" : "waiting";
+    var waiting =
+        chrome.extension.inIncognitoContext ? "waiting_incognito" : "waiting";
     chrome.test.sendMessage(waiting, function(messageJson) {
-      var message = JSON.parse(messageJson);
+      // We will get empty messages, which are considered a noop.
+      var message = { action: 'noop', isFinalAction: false, namespace: 'sync' };
+      if (messageJson.length != 0) {
+        message = JSON.parse(messageJson);
+      }
       var action = testActions[message.action];
       if (!action) {
         chrome.test.fail("Unknown action: " + message.action);
         return;
       }
-      action.bind(api[message.namespace])(
+      action.bind(chrome.storage[message.namespace])(
           message.isFinalAction ? chrome.test.succeed : next);
     });
   }