Chrome power profiler service

content/browser/power_profiler/power_profiler_service_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 "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
+#include "content/browser/browser_thread_impl.h"
+#include "content/browser/power_profiler/power_profiler_service.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace content {
+
+namespace {
+
+const int kNumEvents = 3;
+const int kNumObservers = 3;
+
+class TestPowerDataProvider : public PowerDataProvider {

[jeremy, 2014/02/17 06:31:13]

// Provide a set number of power events.

[Pan, 2014/02/17 07:53:37]

Done.

+ public:
+  TestPowerDataProvider(int count) : event_number_(count) {}

[jeremy, 2014/02/17 06:31:13]

num_events_to_send ?

[Pan, 2014/02/17 07:53:37]

Done.

+  ~TestPowerDataProvider() {}
+
+  virtual PowerEventVector GetData() OVERRIDE {
+    PowerEventVector events;
+    if (event_number_ == 0)
+      return events;
+
+    PowerEvent event;
+    event.type = PowerEvent::SOC_PACKAGE;
+    event.time = base::TimeTicks::Now();
+    event.value = 1.0;
+    events.push_back(event);
+
+    event_number_--;
+    return events;
+  }
+
+ private:
+  int event_number_;

[jeremy, 2014/02/17 06:31:13]

num_events_to_send_ ?

[Pan, 2014/02/17 07:53:37]

Done.

+  DISALLOW_COPY_AND_ASSIGN(TestPowerDataProvider);
+};
+
+class TestPowerProfilerObserver : public PowerProfilerObserver {
+ public:
+  TestPowerProfilerObserver() : valid_event_count_(0) {}
+  ~TestPowerProfilerObserver() {}
+
+  virtual void OnPowerEvent(const PowerEventVector& events) OVERRIDE {
+    if (IsValidEvent(events[0]))
+      ++valid_event_count_;
+  }
+
+  int valid_event_count() const { return valid_event_count_; }
+
+ private:
+  bool IsValidEvent(const PowerEvent& event) {
+    return event.type == PowerEvent::SOC_PACKAGE &&
+           !event.time.is_null() &&
+           event.value > 0;
+  }
+
+  int valid_event_count_;
+  DISALLOW_COPY_AND_ASSIGN(TestPowerProfilerObserver);
+};
+
+} // namespace
+
+class PowerProfilerServiceTest : public testing::Test {
+ public:
+  void ServiceStartTest() {
+    service_ = new PowerProfilerService(
+        make_scoped_ptr<PowerDataProvider>(
+            new TestPowerDataProvider(kNumEvents)),
+        message_loop_.message_loop_proxy(),
+        base::TimeDelta::FromMilliseconds(5));
+    EXPECT_TRUE(service_->IsAvailable());
+  }
+
+  void AddObserverTest() {
+    for (int index = 0; index < kNumObservers; ++index)
+      service_->AddObserver(&observers_[index]);

[jeremy, 2014/02/17 06:31:13]

Any reason to add more than 1 observer?
The observer system is already used in many places and FOR_EACH_OBSERVER should
just work ?

Not that it really bothers me, but just trying to figure out if there's
something more going on here?

[Pan, 2014/02/17 07:53:37]

thanks, the motivation is simple, to test AddObserver can accept several
observers, and notify all, not aims to test FOR_EACH_OBSERVER. 

+
+    // No PowerEvents received.
+    for (int index = 0; index < kNumObservers; ++index)
+      EXPECT_EQ(observers_[0].valid_event_count(), 0);
+  }
+
+  void RemoveObserverTest() {
+    for (int index = 0; index < kNumObservers; ++index)
+      service_->RemoveObserver(&observers_[index]);
+
+    // Everyone received |kNumEvents| events.
+    for (int index = 0; index < kNumObservers; ++index)
+      EXPECT_EQ(observers_[index].valid_event_count(), kNumEvents);
+  }
+
+  void RunLoopForDelay(base::TimeDelta delay) {
+    message_loop_.PostDelayedTask(
+        FROM_HERE, base::MessageLoop::QuitClosure(), delay);
+    base::RunLoop().Run();
+  }
+
+ protected:
+  PowerProfilerServiceTest() : ui_thread_(BrowserThread::UI, &message_loop_) {}
+  virtual ~PowerProfilerServiceTest() {}
+
+ private:
+  PowerProfilerService* service_;
+  TestPowerProfilerObserver observers_[kNumObservers];
+
+  // UI thread

[jeremy, 2014/02/17 06:31:13]

thread.

[Pan, 2014/02/17 07:53:37]

Done.

+  base::MessageLoopForUI message_loop_;
+  BrowserThreadImpl ui_thread_;
+
+  DISALLOW_COPY_AND_ASSIGN(PowerProfilerServiceTest);
+};
+
+// Test whether PowerProfilerService dispatches power events to observers
+// properly.
+TEST_F(PowerProfilerServiceTest, AvailableService) {
+  ServiceStartTest();
+  AddObserverTest();
+
+  // Wait long enough for all power events dispatched.
+  RunLoopForDelay(base::TimeDelta::FromMilliseconds(40));
+  RemoveObserverTest();
+}
+
+}  // namespace content