Add logging around audio session interruptions

webrtc/modules/audio_device/ios/objc/RTCAudioSession.mm

 /*
  *  Copyright 2016 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 68 matching lines @@
     // hint to enable or disable audio that is secondary.
     [center addObserver:self
                selector:@selector(handleSilenceSecondaryAudioHintNotification:)
                    name:AVAudioSessionSilenceSecondaryAudioHintNotification
                  object:nil];
     // Also track foreground event in order to deal with interruption ended situation.
     [center addObserver:self
                selector:@selector(handleApplicationDidBecomeActive:)
                    name:UIApplicationDidBecomeActiveNotification
                  object:nil];
+    RTCLog(@"RTCAudioSession (%p): init.", self);
   }
   return self;
 }
 
 - (void)dealloc {
   [[NSNotificationCenter defaultCenter] removeObserver:self];
+  RTCLog(@"RTCAudioSession (%p): dealloc.", self);
 }
 
 - (NSString *)description {
   NSString *format =
       @"RTCAudioSession: {\n"
        "  category: %@\n"
        "  categoryOptions: %ld\n"
        "  mode: %@\n"
        "  isActive: %d\n"
        "  sampleRate: %.2f\n"
@@ skipping 55 matching lines @@
 }
 
 - (BOOL)isAudioEnabled {
   @synchronized(self) {
     return _isAudioEnabled;
   }
 }
 
 // TODO(tkchin): Check for duplicates.
 - (void)addDelegate:(id<RTCAudioSessionDelegate>)delegate {
+  RTCLog(@"Adding delegate: (%p)", delegate);
   if (!delegate) {
     return;
   }
   @synchronized(self) {
     _delegates.push_back(delegate);
     [self removeZeroedDelegates];
   }
 }
 
 - (void)removeDelegate:(id<RTCAudioSessionDelegate>)delegate {
+  RTCLog(@"Removing delegate: (%p)", delegate);
   if (!delegate) {
     return;
   }
   @synchronized(self) {
     _delegates.erase(std::remove(_delegates.begin(),
                                  _delegates.end(),
                                  delegate),
                      _delegates.end());
     [self removeZeroedDelegates];
   }
@@ skipping 344 matching lines @@
     case AVAudioSessionSilenceSecondaryAudioHintTypeBegin:
       RTCLog(@"Another application's primary audio has started.");
       break;
     case AVAudioSessionSilenceSecondaryAudioHintTypeEnd:
       RTCLog(@"Another application's primary audio has stopped.");
       break;
   }
 }
 
 - (void)handleApplicationDidBecomeActive:(NSNotification *)notification {
+  RTCLog(@"Application became active after an interruption. Treating as interruption "
+         " end. isInterrupted changed from %d to 0.", self.isInterrupted);
   if (self.isInterrupted) {
-    RTCLog(@"Application became active after an interruption. Treating as interruption end.");
     self.isInterrupted = NO;
     [self updateAudioSessionAfterEvent];
-    [self notifyDidEndInterruptionWithShouldResumeSession:YES];
   }
+  // Always treat application becoming active as an interruption end event.
+  [self notifyDidEndInterruptionWithShouldResumeSession:YES];
 }
 
 #pragma mark - Private
 
 + (NSError *)lockError {
   NSDictionary *userInfo = @{
     NSLocalizedDescriptionKey:
         @"Must call lockForConfiguration before calling this method."
   };
   NSError *error =
@@ skipping 287 matching lines @@
 - (void)notifyDidStopPlayOrRecord {
   for (auto delegate : self.delegates) {
     SEL sel = @selector(audioSessionDidStopPlayOrRecord:);
     if ([delegate respondsToSelector:sel]) {
       [delegate audioSessionDidStopPlayOrRecord:self];
     }
   }
 }
 
 @end