[GCM] Extracting Delayed Task Controller from GCMDesktopDriver

components/gcm_driver/gcm_delayed_task_controller_unittest.cc

+// Copyright 2014 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 "components/gcm_driver/gcm_delayed_task_controller.h"
+
+#include "base/bind.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace gcm {
+
+class GCMDelayedTaskControllerTest : public testing::Test {
+ public:
+  GCMDelayedTaskControllerTest();
+  virtual ~GCMDelayedTaskControllerTest();
+
+  void TestTask();
+
+  GCMDelayedTaskController* controller() { return controller_.get(); }
+
+  int number_of_triggered_tasks() const { return number_of_triggered_tasks_; }
+
+ private:
+  scoped_ptr<GCMDelayedTaskController> controller_;
+  int number_of_triggered_tasks_;
+};
+
+GCMDelayedTaskControllerTest::GCMDelayedTaskControllerTest()
+    : controller_(new GCMDelayedTaskController), number_of_triggered_tasks_(0) {
+}
+
+GCMDelayedTaskControllerTest::~GCMDelayedTaskControllerTest() {
+}
+
+void GCMDelayedTaskControllerTest::TestTask() {
+  ++number_of_triggered_tasks_;
+}
+
+// Tests that a newly created controller forced tasks to be delayed.
+TEST_F(GCMDelayedTaskControllerTest, CannotRunTaskWithoutDelayWhenNew) {
+  EXPECT_FALSE(controller()->CanRunTaskWithoutDelay());
+  EXPECT_EQ(0, number_of_triggered_tasks());
+}
+
+// Tests that tasks can be run after controller is set to ready.
+TEST_F(GCMDelayedTaskControllerTest, CanRunTaskWithoutDelayWhenSetReady) {
+  controller()->SetReady();
+  EXPECT_TRUE(controller()->CanRunTaskWithoutDelay());
+  EXPECT_EQ(0, number_of_triggered_tasks());
+}
+
+// Tests that tasks are triggered when controlles is set to ready.
+TEST_F(GCMDelayedTaskControllerTest, PendingTasksTriggeredWhenSetReady) {

[jianli, 2014/09/09 19:53:18]

I think we can combine all these 3 tests into one since we're not testing
multiple aspects of this class:

TEST_F(...) {
  EXPECT_FALSE(controller()->CanRunTaskWithoutDelay());
  EXPECT_EQ(0, number_of_triggered_tasks());

  controller()->AddTask(...);
  controller()->AddTask(...);

  controller()->SetReady();
  EXPECT_TRUE(controller()->CanRunTaskWithoutDelay());
  EXPECT_EQ(2, number_of_triggered_tasks());
}

[fgorski, 2014/09/09 23:11:43]

Done. I went down to 2, because I didn't want to call SetReady twice.

+  controller()->AddTask(base::Bind(&GCMDelayedTaskControllerTest::TestTask,
+                                   base::Unretained(this)));
+  controller()->AddTask(base::Bind(&GCMDelayedTaskControllerTest::TestTask,
+                                   base::Unretained(this)));
+
+  controller()->SetReady();
+  EXPECT_EQ(2, number_of_triggered_tasks());
+}
+
+}  // namespace gcm