Migrate ProcessesEventRouter to the new task manager

chrome/browser/extensions/api/processes/processes_apitest.cc

 // Copyright (c) 2012 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.
 
 #include "base/command_line.h"
+#include "chrome/browser/extensions/api/processes/processes_api.h"
 #include "chrome/browser/extensions/extension_apitest.h"
-#include "chrome/browser/task_manager/task_manager.h"
 #include "chrome/browser/task_manager/task_manager_browsertest_util.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_dialogs.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "extensions/common/switches.h"
 #include "extensions/test/extension_test_message_listener.h"
 
-using ProcessesApiTest = ExtensionApiTest;
+class ProcessesApiTest : public ExtensionApiTest {
+ public:
+  ProcessesApiTest() {}
+  ~ProcessesApiTest() override {}
+
+  int GetListenersCount() {
+    return extensions::ProcessesAPI::Get(profile())->
+        processes_event_router()->listeners_;
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ProcessesApiTest);
+};
 
 IN_PROC_BROWSER_TEST_F(ProcessesApiTest, Processes) {
   ASSERT_TRUE(RunExtensionTest("processes/api")) << message_;
 }
 
-IN_PROC_BROWSER_TEST_F(ProcessesApiTest, ProcessesVsTaskManager) {
-  // This test is for the old implementation of the task manager. We must
-  // explicitly disable the new one.
-  task_manager::browsertest_util::EnableOldTaskManager();
-
-  // Ensure task manager is not yet updating
-  TaskManagerModel* model = TaskManager::GetInstance()->model();
-  EXPECT_EQ(0, model->update_requests_);
-  EXPECT_EQ(TaskManagerModel::IDLE, model->update_state_);
+IN_PROC_BROWSER_TEST_F(ProcessesApiTest, ProcessesApiListeners) {

[Devlin, 2016/03/03 23:12:43]

I'm honestly not sure how useful this test is as it's been written... Could we
also:
- Check the task manager's refresh rate?
- Add different event listeners?

[afakhry, 2016/03/08 01:37:29]

I added another listener for onUpdatedWithMemory and made sure that the memory
refresh type flag is enabled, and the listeners count is updated.

As for the task manager's refresh rate, This could make the test unpredictable.
The task manager will run at the lowest requested refresh rate by all of its
clients. It's true that we currently cut off at 1 Hz, but this could change.
There are many tests in the task manager itself to make sure the refresh rate is
updated correctly. We could do EXPECT_TRUE(current_tm_refresh_time <=
requested_refresh_time); But I don't see an added benefit. 

+  EXPECT_EQ(0, GetListenersCount());
 
   // Load extension that adds listener in background page
   ExtensionTestMessageListener listener("ready", false);
   ASSERT_TRUE(LoadExtension(
       test_data_dir_.AppendASCII("processes").AppendASCII("onupdated")));
   ASSERT_TRUE(listener.WaitUntilSatisfied());
 
-  // Ensure the task manager has started updating
-  EXPECT_EQ(1, model->update_requests_);
-  EXPECT_EQ(TaskManagerModel::TASK_PENDING, model->update_state_);
-
-  // Now show the task manager and wait for it to be ready
-  chrome::ShowTaskManager(browser());
-
-  EXPECT_EQ(2, model->update_requests_);
-  EXPECT_EQ(TaskManagerModel::TASK_PENDING, model->update_state_);
+  // Ensure the listeners count has changed.
+  EXPECT_EQ(1, GetListenersCount());
 
   // Unload the extension and check that listener count decreases
   UnloadExtension(last_loaded_extension_id());
-  EXPECT_EQ(1, model->update_requests_);
+
+  EXPECT_EQ(0, GetListenersCount());
 }
 
 IN_PROC_BROWSER_TEST_F(ProcessesApiTest, CannotTerminateBrowserProcess) {
   ASSERT_TRUE(RunExtensionTest("processes/terminate-browser-process"))
       << message_;
 }