[MediaSession, Android] Adding visibility tests for MediaSession

content/browser/media/session/media_session_integration_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_integration_browsertest_base.h"
+
+#include "base/command_line.h"
+#include "base/timer/elapsed_timer.h"
+#include "content/browser/media/session/media_session.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/common/content_switches.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 "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+static const char kStartPlayerScript[] =
+    "document.getElementById('long-video').play()";
+static const char kPausePlayerScript[] =
+    "document.getElementById('long-video').pause()";
+}
+
+using content::MediaSessionIntegrationBrowserTestBase;
+
+void MediaSessionIntegrationBrowserTestBase::SetUpOnMainThread() {
+  ContentBrowserTest::SetUpOnMainThread();
+  web_contents_ = shell()->web_contents();
+  media_session_ = MediaSession::Get(web_contents_);
+}
+
+void MediaSessionIntegrationBrowserTestBase::SetUpCommandLine(
+    base::CommandLine* command_line) {
+  command_line->AppendSwitch(
+      switches::kDisableGestureRequirementForMediaPlayback);
+}
+
+void MediaSessionIntegrationBrowserTestBase::LoadTestPage() {
+  TestNavigationObserver navigation_observer(shell()->web_contents(), 1);
+  shell()->LoadURL(GetTestUrl("android/media", "media-session.html"));

[mlamouri (slow - plz ping), 2016/03/23 15:10:16]

Maybe you could move this file in a follow-up? Media session is no longer
android-only.

[Zhiqiang Zhang (Slow), 2016/03/24 18:16:49]

Sure, will do.

+  navigation_observer.Wait();
+}
+
+void MediaSessionIntegrationBrowserTestBase::RunScript(std::string script) {
+  content::ExecuteScriptAndGetValue(
+      web_contents_->GetMainFrame(), script);
+}
+
+// TODO(zqzhang): This method is shared with
+// MediaIntegrationTests. Move it into a general place.
+bool MediaSessionIntegrationBrowserTestBase::ConditionalWait(
+    base::TimeDelta timeout,
+    base::TimeDelta interval,
+    const base::Callback<bool(void)>& callback) {
+  base::ElapsedTimer timer;
+  do {
+    if (callback.Run())
+      return true;
+
+    base::RunLoop run_loop;
+    base::MessageLoop::current()->PostDelayedTask(
+        FROM_HERE, run_loop.QuitClosure(), interval);
+    run_loop.Run();
+  } while (timer.Elapsed() < timeout);
+
+  return false;
+}
+
+bool MediaSessionIntegrationBrowserTestBase::IsMediaSessionActive() {
+  return media_session_->audio_focus_state_for_test() ==
+      MediaSession::State::ACTIVE;
+}
+
+bool MediaSessionIntegrationBrowserTestBase::IsMediaSessionSuspended() {
+  return media_session_->audio_focus_state_for_test() ==
+      MediaSession::State::SUSPENDED;
+}
+
+bool MediaSessionIntegrationBrowserTestBase::IsMediaSessionInactive() {
+  return media_session_->audio_focus_state_for_test() ==
+      MediaSession::State::INACTIVE;
+}
+
+void MediaSessionIntegrationBrowserTestBase
+::TestSessionInactiveWhenHiddenAfterContentPause() {
+  LoadTestPage();
+  RunScript(kStartPlayerScript);
+  ASSERT_TRUE(ConditionalWait(
+      base::TimeDelta::FromSeconds(5), base::TimeDelta::FromMilliseconds(50),

[mlamouri (slow - plz ping), 2016/03/23 15:10:16]

I'm not sure if there is a better way but you pointed it's coming from another
media test file. I will leave it for dalecurtis@ to decide.

[DaleCurtis, 2016/03/24 18:22:41]

there are some testing::Timeout values that you should use instead:

https://code.google.com/p/chromium/codesearch#chromium/src/base/test/test_tim...

There might be some browser test helper for polling for a condition:

https://code.google.com/p/chromium/codesearch#chromium/src/content/public/tes...

+      base::Bind(
+          &MediaSessionIntegrationBrowserTestBase::IsMediaSessionActive,
+          base::Unretained(this))));
+  RunScript(kPausePlayerScript);
+  ASSERT_TRUE(ConditionalWait(
+      base::TimeDelta::FromSeconds(5), base::TimeDelta::FromMilliseconds(50),
+      base::Bind(
+          &MediaSessionIntegrationBrowserTestBase::IsMediaSessionSuspended,
+          base::Unretained(this))));
+  web_contents_->WasHidden();
+  ASSERT_TRUE(ConditionalWait(
+      base::TimeDelta::FromSeconds(5), base::TimeDelta::FromMilliseconds(50),
+      base::Bind(
+          &MediaSessionIntegrationBrowserTestBase::IsMediaSessionInactive,
+          base::Unretained(this))));

[mlamouri (slow - plz ping), 2016/03/23 15:10:15]

Could you improve the readability here? Maybe something like:
{
  LoadTestPage();

  RunScript(...)
  ASSERT_TRUE(...);

  RunScript(...);
  ASSERT_TRUE(...);

  RunScript(...);
  ASSERT_TRUE(..);
}

same below.

[Zhiqiang Zhang (Slow), 2016/03/24 18:16:49]

Done.

+}
+
+void MediaSessionIntegrationBrowserTestBase
+::TestSessionInactiveWhenHiddenWhilePlaying() {
+  LoadTestPage();
+  RunScript(kStartPlayerScript);
+  ASSERT_TRUE(ConditionalWait(
+      base::TimeDelta::FromSeconds(5), base::TimeDelta::FromMilliseconds(50),
+      base::Bind(
+          &MediaSessionIntegrationBrowserTestBase::IsMediaSessionActive,
+          base::Unretained(this))));
+  web_contents_->WasHidden();
+  ASSERT_TRUE(ConditionalWait(
+      base::TimeDelta::FromSeconds(5), base::TimeDelta::FromMilliseconds(50),
+      base::Bind(
+          &MediaSessionIntegrationBrowserTestBase::IsMediaSessionInactive,
+          base::Unretained(this))));
+}

[mlamouri (slow - plz ping), 2016/03/23 15:10:16]

Could you have these tests with kEnableMediaSuspend and kDisableMediaSuspend? 

https://code.google.com/p/chromium/codesearch#chromium/src/media/base/media_s...

[Zhiqiang Zhang (Slow), 2016/03/24 18:16:49]

Done.