Support running cast apps in background.

This CL should allow Cast apps to run in the background on Android TV
while playing nicely with other apps. This includes:

* Disable kRequestSystemAudioFocus on Cast apps so Cast can manage audio
  focus.
* Stop cast apps when audio focus is lost.
* Don't tear down/finish CastWebContentsActivity when the user leaves.

Bug: internal b/143313649, internal b/142828228
Test: manual
Merge-With: eureka-internal/359240
Change-Id: I2ac25f7e0749abfdac2bb2ab98010f7489787f25
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2036519
Auto-Submit: Thoren Paulson <thoren@chromium.org>
Reviewed-by: Simeon Anfinrud <sanfin@chromium.org>
Reviewed-by: Luke Halliwell (slow) <halliwell@chromium.org>
Reviewed-by: Becca Hughes <beccahughes@chromium.org>
Commit-Queue: Luke Halliwell (slow) <halliwell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#738974}

chromecast/browser/android/apk/AndroidManifest.xml.jinja2

@@ -33,7 +33,7 @@
                   android:screenOrientation="landscape"
                   android:taskAffinity=".CastWebContentsActivity"
                   android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|layoutDirection"
-                  android:excludeFromRecents="true"
+                  android:excludeFromRecents="false"
                   {% if cast_build_enable_background_activities == "true" %}
                   android:noHistory="false">
                   {% else %}

chromecast/browser/android/apk/src/org/chromium/chromecast/shell/CastAudioFocusRequest.java

@@ -64,6 +64,11 @@ public class CastAudioFocusRequest {
 
     void setAudioFocusChangeListener(AudioManager.OnAudioFocusChangeListener l) {
         mAudioFocusChangeListener = l;
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O && mAudioFocusRequest != null) {
+            mAudioFocusRequest = new AudioFocusRequest.Builder(mAudioFocusRequest)
+                                         .setOnAudioFocusChangeListener(mAudioFocusChangeListener)
+                                         .build();
+        }
     }
 
     int request(AudioManager audioManager) {

chromecast/browser/android/apk/src/org/chromium/chromecast/shell/CastAudioManager.java

@@ -65,7 +65,7 @@ public class CastAudioManager {
     public Observable<AudioFocusLoss> requestAudioFocusWhen(
             Observable<CastAudioFocusRequest> event) {
         Controller<AudioFocusLoss> audioFocusLossState = new Controller<>();
-        audioFocusLossState.set(AudioFocusLoss.NORMAL);
+        audioFocusLossState.set(AudioFocusLoss.NOT_REQUESTED);
         event.subscribe(focusRequest -> {
             focusRequest.setAudioFocusChangeListener((int focusChange) -> {
                 audioFocusLossState.set(AudioFocusLoss.from(focusChange));
@@ -139,7 +139,8 @@ public class CastAudioManager {
     public enum AudioFocusLoss {
         NORMAL,
         TRANSIENT,
-        TRANSIENT_CAN_DUCK;
+        TRANSIENT_CAN_DUCK,
+        NOT_REQUESTED;
 
         private static @Nullable AudioFocusLoss from(int focusChange) {
             switch (focusChange) {

chromecast/browser/android/apk/src/org/chromium/chromecast/shell/CastWebContentsActivity.java

@@ -48,8 +48,6 @@ public class CastWebContentsActivity extends Activity {
     private final Controller<Unit> mResumedState = new Controller<>();
     // Tracks whether this Activity is between onStart() and onStop().
     private final Controller<Unit> mStartedState = new Controller<>();
-    // Tracks whether the user has left according to onUserLeaveHint().
-    private final Controller<Unit> mUserLeftState = new Controller<>();
     // Tracks the most recent Intent for the Activity.
     private final Controller<Intent> mGotIntentState = new Controller<>();
     // Set this to cause the Activity to finish.
@@ -128,6 +126,17 @@ public class CastWebContentsActivity extends Activity {
                     audioManager.releaseStreamMuteIfNecessary(AudioManager.STREAM_MUSIC);
                 }));
 
+        final Observable<CastAudioFocusRequest> audioFocusRequestState = mCreatedState.map(x
+                -> new CastAudioFocusRequest.Builder()
+                           .setFocusGain(AudioManager.AUDIOFOCUS_GAIN)
+                           .build());
+
+        mAudioManagerState.subscribe((CastAudioManager audioManager) -> {
+            return audioManager.requestAudioFocusWhen(audioFocusRequestState)
+                    .filter(state -> state == CastAudioManager.AudioFocusLoss.NORMAL)
+                    .subscribe(Observers.onEnter(x -> mIsFinishingState.set("Lost audio focus.")));
+        });
+
         // Handle each new Intent.
         Controller<CastWebContentsSurfaceHelper.StartParams> startParamsState = new Controller<>();
         mGotIntentState.and(Observable.not(mIsFinishingState))
@@ -154,11 +163,6 @@ public class CastWebContentsActivity extends Activity {
             intent.setFlags(flags);
             startActivity(intent);
         }));
-
-        Observable<?> stoppingBecauseUserLeftState =
-                Observable.not(mStartedState).and(mUserLeftState);
-        stoppingBecauseUserLeftState.subscribe(
-                Observers.onEnter(x -> mIsFinishingState.set("User left and activity stopped.")));
     }
 
     @Override
@@ -215,12 +219,6 @@ public class CastWebContentsActivity extends Activity {
         super.onDestroy();
     }
 
-    @Override
-    protected void onUserLeaveHint() {
-        mUserLeftState.set(Unit.unit());
-        super.onUserLeaveHint();
-    }
-
     @Override
     public void onWindowFocusChanged(boolean hasFocus) {
         if (DEBUG) Log.d(TAG, "onWindowFocusChanged(%b)", hasFocus);

chromecast/browser/android/apk/src/org/chromium/chromecast/shell/CastWebContentsSurfaceHelper.java

@@ -115,6 +115,7 @@ class CastWebContentsSurfaceHelper {
         Controller<WebContents> webContentsState = new Controller<>();
         mStartParamsState.map(params -> params.webContents)
                 .subscribe(Observers.onEnter(webContentsState::set));
+        mCreatedState.subscribe(Observers.onExit(x -> webContentsState.reset()));
 
         // Receive broadcasts indicating the screen turned off while we have active WebContents.
         uriState.subscribe((Uri uri) -> {

chromecast/browser/android/junit/src/org/chromium/chromecast/shell/CastAudioManagerTest.java

@@ -51,9 +51,9 @@ public class CastAudioManagerTest {
         Observable<CastAudioManager.AudioFocusLoss> lostAudioFocusState =
                 audioManager.requestAudioFocusWhen(requestAudioFocusState);
         ReactiveRecorder lostAudioFocusRecorder = ReactiveRecorder.record(lostAudioFocusState);
-        lostAudioFocusRecorder.verify().opened(CastAudioManager.AudioFocusLoss.NORMAL).end();
+        lostAudioFocusRecorder.verify().opened(CastAudioManager.AudioFocusLoss.NOT_REQUESTED).end();
         requestAudioFocusState.set(buildFocusRequest());
-        lostAudioFocusRecorder.verify().closed(CastAudioManager.AudioFocusLoss.NORMAL).end();
+        lostAudioFocusRecorder.verify().closed(CastAudioManager.AudioFocusLoss.NOT_REQUESTED).end();
     }
 
     @Test
@@ -66,11 +66,11 @@ public class CastAudioManagerTest {
         Observable<CastAudioManager.AudioFocusLoss> lostAudioFocusState =
                 audioManager.requestAudioFocusWhen(requestAudioFocusState);
         ReactiveRecorder lostAudioFocusRecorder = ReactiveRecorder.record(lostAudioFocusState);
-        lostAudioFocusRecorder.verify().opened(CastAudioManager.AudioFocusLoss.NORMAL).end();
+        lostAudioFocusRecorder.verify().opened(CastAudioManager.AudioFocusLoss.NOT_REQUESTED).end();
         requestAudioFocusState.set(buildFocusRequest());
         shadowAudioManager.getLastAudioFocusRequest().listener.onAudioFocusChange(
                 AudioManager.AUDIOFOCUS_GAIN);
-        lostAudioFocusRecorder.verify().closed(CastAudioManager.AudioFocusLoss.NORMAL).end();
+        lostAudioFocusRecorder.verify().closed(CastAudioManager.AudioFocusLoss.NOT_REQUESTED).end();
         requestAudioFocusState.reset();
         lostAudioFocusRecorder.verify().opened(CastAudioManager.AudioFocusLoss.NORMAL).end();
     }
@@ -85,12 +85,12 @@ public class CastAudioManagerTest {
         Observable<CastAudioManager.AudioFocusLoss> lostAudioFocusState =
                 audioManager.requestAudioFocusWhen(requestAudioFocusState);
         ReactiveRecorder lostAudioFocusRecorder = ReactiveRecorder.record(lostAudioFocusState);
-        lostAudioFocusRecorder.verify().opened(CastAudioManager.AudioFocusLoss.NORMAL).end();
+        lostAudioFocusRecorder.verify().opened(CastAudioManager.AudioFocusLoss.NOT_REQUESTED).end();
         requestAudioFocusState.set(buildFocusRequest());
         AudioManager.OnAudioFocusChangeListener listener =
                 shadowAudioManager.getLastAudioFocusRequest().listener;
         listener.onAudioFocusChange(AudioManager.AUDIOFOCUS_GAIN);
-        lostAudioFocusRecorder.verify().closed(CastAudioManager.AudioFocusLoss.NORMAL).end();
+        lostAudioFocusRecorder.verify().closed(CastAudioManager.AudioFocusLoss.NOT_REQUESTED).end();
         listener.onAudioFocusChange(AudioManager.AUDIOFOCUS_LOSS);
         lostAudioFocusRecorder.verify().opened(CastAudioManager.AudioFocusLoss.NORMAL).end();
     }
@@ -105,12 +105,12 @@ public class CastAudioManagerTest {
         Observable<CastAudioManager.AudioFocusLoss> lostAudioFocusState =
                 audioManager.requestAudioFocusWhen(requestAudioFocusState);
         ReactiveRecorder lostAudioFocusRecorder = ReactiveRecorder.record(lostAudioFocusState);
-        lostAudioFocusRecorder.verify().opened(CastAudioManager.AudioFocusLoss.NORMAL).end();
+        lostAudioFocusRecorder.verify().opened(CastAudioManager.AudioFocusLoss.NOT_REQUESTED).end();
         requestAudioFocusState.set(buildFocusRequest());
         AudioManager.OnAudioFocusChangeListener listener =
                 shadowAudioManager.getLastAudioFocusRequest().listener;
         listener.onAudioFocusChange(AudioManager.AUDIOFOCUS_GAIN);
-        lostAudioFocusRecorder.verify().closed(CastAudioManager.AudioFocusLoss.NORMAL).end();
+        lostAudioFocusRecorder.verify().closed(CastAudioManager.AudioFocusLoss.NOT_REQUESTED).end();
         listener.onAudioFocusChange(AudioManager.AUDIOFOCUS_LOSS);
         lostAudioFocusRecorder.verify().opened(CastAudioManager.AudioFocusLoss.NORMAL).end();
         listener.onAudioFocusChange(AudioManager.AUDIOFOCUS_GAIN);
@@ -126,7 +126,7 @@ public class CastAudioManagerTest {
         Observable<CastAudioManager.AudioFocusLoss> lostAudioFocusState =
                 audioManager.requestAudioFocusWhen(requestAudioFocusState);
         ReactiveRecorder lostAudioFocusRecorder = ReactiveRecorder.record(lostAudioFocusState);
-        lostAudioFocusRecorder.verify().opened(CastAudioManager.AudioFocusLoss.NORMAL).end();
+        lostAudioFocusRecorder.verify().opened(CastAudioManager.AudioFocusLoss.NOT_REQUESTED).end();
     }
 
     @Test

chromecast/browser/android/junit/src/org/chromium/chromecast/shell/CastWebContentsActivityTest.java

@@ -11,6 +11,7 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.reset;
 import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
 
 import android.app.Activity;
 import android.content.Intent;
@@ -35,6 +36,7 @@ import org.robolectric.annotation.Implements;
 import org.robolectric.shadow.api.Shadow;
 import org.robolectric.shadows.ShadowActivity;
 
+import org.chromium.chromecast.base.Observable;
 import org.chromium.content_public.browser.WebContents;
 import org.chromium.testing.local.LocalRobolectricTestRunner;
 
@@ -109,6 +111,8 @@ public class CastWebContentsActivityTest {
     @Test
     public void testReleasesStreamMuteIfNecessaryOnPause() {
         CastAudioManager mockAudioManager = mock(CastAudioManager.class);
+        when(mockAudioManager.requestAudioFocusWhen(anyObject()))
+                .thenReturn(mock(Observable.class));
         mActivity.setAudioManagerForTesting(mockAudioManager);
         mActivityLifecycle.create().start().resume();
         mActivityLifecycle.pause();
@@ -239,22 +243,6 @@ public class CastWebContentsActivityTest {
         Assert.assertFalse(mShadowActivity.isFinishing());
     }
 
-    @Test
-    public void testUserLeaveAndStopCausesFinish() {
-        mActivityLifecycle.create().start().resume();
-        mActivityLifecycle.pause().userLeaving().stop();
-        Assert.assertTrue(mShadowActivity.isFinishing());
-    }
-
-    @Test
-    public void testUserLeaveAndStopDestroysSurfaceHelper() {
-        CastWebContentsSurfaceHelper surfaceHelper = mock(CastWebContentsSurfaceHelper.class);
-        mActivity.setSurfaceHelperForTesting(surfaceHelper);
-        mActivityLifecycle.create().start().resume();
-        mActivityLifecycle.pause().userLeaving().stop();
-        verify(surfaceHelper).onDestroy();
-    }
-
     @Test
     public void testOnDestroyDestroysSurfaceHelper() {
         CastWebContentsSurfaceHelper surfaceHelper = mock(CastWebContentsSurfaceHelper.class);

chromecast/browser/android/junit/src/org/chromium/chromecast/shell/CastWebContentsSurfaceHelperTest.java

@@ -333,6 +333,6 @@ public class CastWebContentsSurfaceHelperTest {
         when(mWebContentsView.open(webContents)).thenReturn(scope);
         mSurfaceHelper.onNewStartParams(params);
         mSurfaceHelper.onDestroy();
-        verify(scope, never()).close();
+        verify(scope).close();
     }
 }

chromecast/browser/cast_content_browser_client.cc

@@ -161,6 +161,7 @@ CastContentBrowserClient::CastContentBrowserClient(
 #if defined(OS_ANDROID)
   cast_feature_list_creator_->SetExtraDisableFeatures({
       ::media::kAudioFocusLossSuspendMediaSession,
+      ::media::kRequestSystemAudioFocus,
   });
 #endif
 }

content/browser/media/session/audio_focus_delegate_android.cc

@@ -35,6 +35,9 @@ void AudioFocusDelegateAndroid::Initialize() {
 AudioFocusDelegate::AudioFocusResult
 AudioFocusDelegateAndroid::RequestAudioFocus(
     media_session::mojom::AudioFocusType audio_focus_type) {
+  if (!base::FeatureList::IsEnabled(media::kRequestSystemAudioFocus))
+    return AudioFocusDelegate::AudioFocusResult::kSuccess;
+
   JNIEnv* env = base::android::AttachCurrentThread();
   DCHECK(env);
   bool success = Java_AudioFocusDelegate_requestAudioFocus(

media/base/media_switches.cc

@@ -524,6 +524,11 @@ const base::Feature kCanPlayHls{"CanPlayHls", base::FEATURE_ENABLED_BY_DEFAULT};
 // HLS manifests will fail to load (triggering source fallback or load error).
 const base::Feature kHlsPlayer{"HlsPlayer", base::FEATURE_ENABLED_BY_DEFAULT};
 
+// When enabled, Playing media sessions will request audio focus from the
+// Android system.
+const base::Feature kRequestSystemAudioFocus{"RequestSystemAudioFocus",
+                                             base::FEATURE_ENABLED_BY_DEFAULT};
+
 // Use the (hacky) AudioManager.getOutputLatency() call to get the estimated
 // hardware latency for a stream for OpenSLES playback.  This is normally not
 // needed, except for some Android TV devices.

media/base/media_switches.h

@@ -179,6 +179,7 @@ MEDIA_EXPORT extern const base::Feature kDisableSurfaceLayerForVideo;
 MEDIA_EXPORT extern const base::Feature kCanPlayHls;
 MEDIA_EXPORT extern const base::Feature kPictureInPictureAPI;
 MEDIA_EXPORT extern const base::Feature kHlsPlayer;
+MEDIA_EXPORT extern const base::Feature kRequestSystemAudioFocus;
 MEDIA_EXPORT extern const base::Feature kUseAudioLatencyFromHAL;
 MEDIA_EXPORT extern const base::Feature kUsePooledSharedImageVideoProvider;
 #endif  // defined(OS_ANDROID)