[SystemInfo API] Implement systemInfo.storage.onAvailableCapacityChanged event

chrome/test/data/extensions/api_test/systeminfo/storage/test_storage_api.js

Index: chrome/test/data/extensions/api_test/systeminfo/storage/test_storage_api.js
diff --git a/chrome/test/data/extensions/api_test/systeminfo/storage/test_storage_api.js b/chrome/test/data/extensions/api_test/systeminfo/storage/test_storage_api.js
index 06c9c658cb5d50d7db2e313597479bca57cfd3ec..a679dd88812f958c6f0f2f251d7788a84713bf51 100644
--- a/chrome/test/data/extensions/api_test/systeminfo/storage/test_storage_api.js
+++ b/chrome/test/data/extensions/api_test/systeminfo/storage/test_storage_api.js
@@ -3,34 +3,57 @@
 // found in the LICENSE file.
 
 // systemInfo.storage api test
-// browser_tests.exe --gtest_filter=SystemInfoStorageApiTest.Storage
+// browser_tests --gtest_filter=SystemInfoStorageApiTest.Storage
 chrome.systemInfo = chrome.experimental.systemInfo;
 
+// Testing data should be the same as that in system_info_storage_apitest.cc
+var testData = [
+  { id: "0xbeaf", type: "unknown", capacity: 4098,
+    availableCapacity: 1000, step: 0 },
+  { id: "/home", type: "harddisk", capacity: 4098,
+    availableCapacity: 1000, step: 10 },
+  { id: "/data", type: "harddisk", capacity: 10000,
+    availableCapacity: 1000, step: 4097 }
+];
+
 chrome.test.runTests([
   function testGet() {
     chrome.systemInfo.storage.get(chrome.test.callbackPass(function(units) {
-      chrome.test.assertTrue(units.length == 1);
-      var unit = units[0];
-      chrome.test.assertTrue(unit.id == "0xbeaf");
-      chrome.test.assertTrue(unit.type == "unknown");
-      chrome.test.assertTrue(unit.capacity == 4098);
-      chrome.test.assertTrue(unit.availableCapacity == 1024);
+      chrome.test.assertTrue(units.length == 3);
+      for (var i = 0; i < units.length; ++i) {
+        chrome.test.assertEq(testData[i].id, units[i].id);
+        chrome.test.assertEq(testData[i].type, units[i].type);
+        chrome.test.assertEq(testData[i].capacity, units[i].capacity);
+        chrome.test.assertEq(testData[i].availableCapacity,
+                             units[i].availableCapacity);
+        testData[i].availableCapacity += testData[i].step;
+      }
     }));
   },
   function testChangedEvent() {
-    chrome.test.sendMessage("ready", function() {
-      var numOfChangedEvent = 0;
-      var base = 10000;
-      var step = 10;
-      var doneChangedEvent = chrome.test.listenForever(
-        chrome.systemInfo.storage.onAvailableCapacityChanged,
-        function listener(changedInfo) {
-          chrome.test.assertTrue(changedInfo.id == "/dev/sda1");
-          chrome.test.assertTrue(
-            changedInfo.availableCapacity == (base - step*numOfChangedEvent));
-          if (++numOfChangedEvent > 5)
-            doneChangedEvent();
-        });
-      });
-    }
+    var numOfChangedEvent = 0;
+    var callbackCompleted = chrome.test.callbackAdded();
+    chrome.systemInfo.storage.onAvailableCapacityChanged.addListener(
+      function listener(changeInfo) {
+        for (var i = 0; i < testData.length; ++i) {
+          if (changeInfo.id == testData[i].id) {
+            // Increase its availableCapacity since it will be queried before
+            // triggering onChanged event.
+            testData[i].availableCapacity += testData[i].step;
+            chrome.test.assertEq(testData[i].availableCapacity,
+                                  changeInfo.availableCapacity);
+            break;
+          }
+        }
+
+        if (i >= testData.length)
+          chrome.test.fail("No matched storage id is found!");
+
+        if (++numOfChangedEvent > 10) {
+          chrome.systemInfo.storage.onAvailableCapacityChanged.removeListener(
+            listener);
+          setTimeout(callbackCompleted, 0);
+        }
+     });
+   }
 ]);