Added audioSessionDidActivate and audioSessionDidDectivate

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 769 matching lines @@
       return;
     }
     _canPlayOrRecord = canPlayOrRecord;
     shouldNotify = YES;
   }
   if (shouldNotify) {
     [self notifyDidChangeCanPlayOrRecord:canPlayOrRecord];
   }
 }
 
+- (void)audioSessionDidActivate:(AVAudioSession *)session {
+  if (_session != session) {
+    RTCLogError(@"audioSessionDidActivate called on different AVAudioSession");
+  }
+  [self incrementActivationCount];
+  self.isActive = YES;
+}
+
+- (void)audioSessionDidDeactivate:(AVAudioSession *)session {
+  if (_session != session) {
+    RTCLogError(@"audioSessionDidDeactivate called on different AVAudioSession");
+  }
+  self.isActive = NO;
+  [self decrementActivationCount];
+}
+
 - (void)notifyDidBeginInterruption {
   for (auto delegate : self.delegates) {
     SEL sel = @selector(audioSessionDidBeginInterruption:);
     if ([delegate respondsToSelector:sel]) {
       [delegate audioSessionDidBeginInterruption:self];
     }
   }
 }
 
 - (void)notifyDidEndInterruptionWithShouldResumeSession:
@@ skipping 58 matching lines @@
 - (void)notifyDidStopPlayOrRecord {
   for (auto delegate : self.delegates) {
     SEL sel = @selector(audioSessionDidStopPlayOrRecord:);
     if ([delegate respondsToSelector:sel]) {
       [delegate audioSessionDidStopPlayOrRecord:self];
     }
   }
 }
 
 @end