[MediaSession, Android] Adding visibility tests for MediaSession

content/browser/media/session/media_session_visibility_browsertest_base.cc

+// Copyright 2016 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 "content/browser/media/session/media_session_visibility_browsertest_base.h"
+
+#include "base/command_line.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/common/content_switches.h"
+#include "content/public/test/browser_test_utils.h"
+#include "content/public/test/content_browser_test_utils.h"
+#include "content/public/test/test_navigation_observer.h"
+#include "content/shell/browser/shell.h"
+#include "media/base/media_switches.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace content {
+namespace {
+static const char kStartPlayerScript[] =
+    "document.getElementById('long-video').play()";
+static const char kPausePlayerScript[] =
+    "document.getElementById('long-video').pause()";
+}
+
+MediaSessionVisibilityBrowserTestBase::
+    MediaSessionVisibilityBrowserTestBase() {

[DaleCurtis, 2016/03/31 16:50:26]

Is this the style that git cl format applied? It seems a bit unusual to have a
four space indent on the following line.

[Zhiqiang Zhang (Slow), 2016/03/31 19:58:39]

Done.

+}
+
+MediaSessionVisibilityBrowserTestBase::
+    ~MediaSessionVisibilityBrowserTestBase() {
+}
+
+void MediaSessionVisibilityBrowserTestBase::SetUpOnMainThread() {
+  ContentBrowserTest::SetUpOnMainThread();
+  web_contents_ = shell()->web_contents();
+  media_session_ = MediaSession::Get(web_contents_);
+
+  media_session_state_loop_runners_[MediaSession::State::ACTIVE] =
+      new MessageLoopRunner;

[DaleCurtis, 2016/03/31 16:50:26]

() after class name. ditto for all "new XXX" below.

[Zhiqiang Zhang (Slow), 2016/03/31 19:58:39]

Done.

+  media_session_state_loop_runners_[MediaSession::State::SUSPENDED] =
+      new MessageLoopRunner;
+  media_session_state_loop_runners_[MediaSession::State::INACTIVE] =
+      new MessageLoopRunner;
+  media_session_state_callback_subscription_ =
+      media_session_->RegisterMediaSessionStateChangedCallbackForTest(
+          base::Bind(&MediaSessionVisibilityBrowserTestBase::
+                         OnMediaSessionStateChanged,
+                     base::Unretained(this)));
+}
+
+void MediaSessionVisibilityBrowserTestBase::TearDownOnMainThread() {
+  // Unsubscribe the callback subscription before tearing down, so that the
+  // CallbackList in MediaSession will be empty when it is destroyed.
+  media_session_state_callback_subscription_.reset();
+}
+
+void MediaSessionVisibilityBrowserTestBase::SetUpCommandLine(
+    base::CommandLine* command_line) {
+  command_line->AppendSwitch(
+      switches::kDisableGestureRequirementForMediaPlayback);
+#if !defined(OS_ANDROID)
+  command_line->AppendSwitch(
+      switches::kEnableDefaultMediaSession);
+#endif  // !defined(OS_ANDROID)
+}
+
+void MediaSessionVisibilityBrowserTestBase::LoadTestPage() {
+  TestNavigationObserver navigation_observer(shell()->web_contents(), 1);
+  shell()->LoadURL(GetTestUrl("android/media", "media-session.html"));
+  navigation_observer.Wait();
+}
+
+void MediaSessionVisibilityBrowserTestBase::RunScript(std::string script) {

[DaleCurtis, 2016/03/31 16:50:26]

const& for strings.

[Zhiqiang Zhang (Slow), 2016/03/31 19:58:39]

Done.

+  ASSERT_TRUE(ExecuteScript(web_contents_->GetMainFrame(), script));
+}
+
+void MediaSessionVisibilityBrowserTestBase::
+ClearMediaSessionStateLoopRunners() {
+  for (auto& state_loop_runner : media_session_state_loop_runners_)
+    state_loop_runner.second = new MessageLoopRunner;

[DaleCurtis, 2016/03/31 16:50:26]

()

[Zhiqiang Zhang (Slow), 2016/03/31 19:58:39]

Done.

+}
+
+void MediaSessionVisibilityBrowserTestBase::OnMediaSessionStateChanged(
+    MediaSession::State state) {
+  ASSERT_TRUE(media_session_state_loop_runners_.count(state));
+  media_session_state_loop_runners_[state]->Quit();
+}
+
+

[DaleCurtis, 2016/03/31 16:50:26]

Extra line.

[Zhiqiang Zhang (Slow), 2016/03/31 19:58:39]

Done.

+void MediaSessionVisibilityBrowserTestBase::Wait(base::TimeDelta timeout) {

[DaleCurtis, 2016/03/31 16:50:26]

You don't really need this, but up to you. THe browser tests have built in
timeouts that will be applied. You could just use base::RunLoop().Run(), though
this may result in cleaner error messages it may be flaky on the slower bots.

[Zhiqiang Zhang (Slow), 2016/03/31 19:58:39]

I think we still need this since this is for verifying something NOT happen.
e.g. If we don't want MediaSession go suspended/inactive after some action, I
have to wait for a short time and check the state. The browser test timeout
might be longer than the media duration, and the MediaSession will go inactive.

We have met the same issue in MediaSessionTest.java. The way we are doing now
might be flaky, but we still don't have better solution yet.

+  base::RunLoop run_loop;
+  base::MessageLoop::current()->PostDelayedTask(
+      FROM_HERE, run_loop.QuitClosure(), timeout);
+  run_loop.Run();
+}
+
+void MediaSessionVisibilityBrowserTestBase::WaitForMediaSessionState(
+    MediaSession::State state) {
+  ASSERT_TRUE(media_session_state_loop_runners_.count(state));
+  media_session_state_loop_runners_[state]->Run();
+}
+
+void MediaSessionVisibilityBrowserTestBase::
+    TestSessionInactiveWhenHiddenAfterContentPause() {
+  LoadTestPage();
+
+  ClearMediaSessionStateLoopRunners();
+  RunScript(kStartPlayerScript);
+  WaitForMediaSessionState(MediaSession::State::ACTIVE);
+
+  ClearMediaSessionStateLoopRunners();
+  RunScript(kPausePlayerScript);
+  WaitForMediaSessionState(MediaSession::State::SUSPENDED);
+
+  ClearMediaSessionStateLoopRunners();
+  web_contents_->WasHidden();
+  WaitForMediaSessionState(MediaSession::State::INACTIVE);
+}
+
+void MediaSessionVisibilityBrowserTestBase::
+    TestSessionInactiveWhenHiddenWhilePlaying() {
+  LoadTestPage();
+
+  ClearMediaSessionStateLoopRunners();
+  RunScript(kStartPlayerScript);
+  WaitForMediaSessionState(MediaSession::State::ACTIVE);
+
+  ClearMediaSessionStateLoopRunners();
+  web_contents_->WasHidden();
+  WaitForMediaSessionState(MediaSession::State::INACTIVE);
+}
+
+void MediaSessionVisibilityBrowserTestBase::
+    TestSessionSuspendedWhenHiddenAfterContentPause() {
+  LoadTestPage();
+
+  ClearMediaSessionStateLoopRunners();
+  RunScript(kStartPlayerScript);
+  WaitForMediaSessionState(MediaSession::State::ACTIVE);
+
+  ClearMediaSessionStateLoopRunners();
+  RunScript(kPausePlayerScript);
+  WaitForMediaSessionState(MediaSession::State::SUSPENDED);
+
+  // Wait for 1 second and check the MediaSession state.
+  // No better solution till now.
+  web_contents_->WasHidden();
+  Wait(base::TimeDelta::FromSeconds(1));
+  ASSERT_EQ(media_session_->audio_focus_state_, MediaSession::State::SUSPENDED);
+}
+
+void MediaSessionVisibilityBrowserTestBase::
+    TestSessionActiveWhenHiddenWhilePlaying() {
+  LoadTestPage();
+
+  ClearMediaSessionStateLoopRunners();
+  RunScript(kStartPlayerScript);
+  WaitForMediaSessionState(MediaSession::State::ACTIVE);
+
+  // Wait for 1 second and check the MediaSession state.
+  // No better solution till now.
+  web_contents_->WasHidden();
+  Wait(base::TimeDelta::FromSeconds(1));
+  ASSERT_EQ(media_session_->audio_focus_state_, MediaSession::State::ACTIVE);
+}
+
+}  // namespace content