iOS audio session isInterrupted flag does not get reset correctly:

webrtc/modules/audio_device/ios/objc/RTCAudioSessionTest.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.
  */
 
 #import <Foundation/Foundation.h>
 #import <OCMock/OCMock.h>
 
+// Allow private members to be accessed for testing purposes
+#define private public

[tkchin_webrtc, 2017/05/09 17:48:25]

oof. Don't do this - not good to redefine keywords, even in tests. It will
eventually come back to bother us.

+#include "webrtc/modules/audio_device/ios/audio_device_ios.h"
 #include "webrtc/test/gtest.h"
 
 #import "webrtc/modules/audio_device/ios/objc/RTCAudioSession.h"
 #import "webrtc/modules/audio_device/ios/objc/RTCAudioSession+Private.h"
 #import "webrtc/modules/audio_device/ios/objc/RTCAudioSessionConfiguration.h"
 
 @interface RTCAudioSessionTestDelegate : NSObject <RTCAudioSessionDelegate>
 @end
 
 @implementation RTCAudioSessionTestDelegate
@@ skipping 215 matching lines @@
   [audioSession unlockForConfiguration];
 
   OCMVerify([mockAudioSession session]);
   OCMVerify([[mockAVAudioSession ignoringNonObjectArgs] setActive:YES withOptions:0 error:&error]);
   OCMVerify([[mockAVAudioSession ignoringNonObjectArgs] setActive:NO withOptions:0 error:&error]);
 
   [mockAVAudioSession stopMocking];
   [mockAudioSession stopMocking];
 }
 
+- (void)testInterruptedAudioSession {

[tkchin_webrtc, 2017/05/09 17:48:25]

this belongs in:
https://cs.chromium.org/chromium/src/third_party/webrtc/modules/audio_device/...

+  RTCAudioSession *session = [RTCAudioSession sharedInstance];
+  webrtc::AudioDeviceIOS  *audioDevice = new webrtc::AudioDeviceIOS();
+  webrtc::AudioDeviceBuffer *audioBuffer = new webrtc::AudioDeviceBuffer();
+  audioDevice->AttachAudioBuffer(audioBuffer);
+  audioDevice->Init();
+  audioDevice->InitPlayout();
+  [session notifyDidBeginInterruption]; // force interruption
+
+  // Wait for notification to propagate
+  rtc::MessageQueueManager::ProcessAllMessageQueues();
+  EXPECT_TRUE(audioDevice->is_interrupted_);
+
+  audioDevice->playing_ = false;  // force it for testing
+  audioDevice->ShutdownPlayOrRecord();
+  audioDevice->audio_is_initialized_ = false; // force it for testing
+
+  [session notifyDidEndInterruptionWithShouldResumeSession:YES];
+  // Wait for notification to propagate
+  rtc::MessageQueueManager::ProcessAllMessageQueues();
+  EXPECT_TRUE(audioDevice->is_interrupted_);
+
+  audioDevice->Init();
+  audioDevice->InitPlayout();
+  EXPECT_FALSE(audioDevice->is_interrupted_);
+  delete audioBuffer;

[tkchin_webrtc, 2017/05/09 17:48:25]

fyi it is extremely rare to use delete now since unique_ptr is available

[jtt_webrtc, 2017/05/09 19:07:45]

Done.

+  delete audioDevice;
+}
+
 @end
 
 namespace webrtc {
 
 class AudioSessionTest : public ::testing::Test {
  protected:
   void TearDown() {
     RTCAudioSession *session = [RTCAudioSession sharedInstance];
     for (id<RTCAudioSessionDelegate> delegate : session.delegates) {
       [session removeDelegate:delegate];
@@ skipping 29 matching lines @@
 TEST_F(AudioSessionTest, AudioSessionActivation) {
   RTCAudioSessionTest *test = [[RTCAudioSessionTest alloc] init];
   [test testAudioSessionActivation];
 }
 
 TEST_F(AudioSessionTest, ConfigureWebRTCSession) {
   RTCAudioSessionTest *test = [[RTCAudioSessionTest alloc] init];
   [test testConfigureWebRTCSession];
 }
 
+TEST_F(AudioSessionTest, testInterruptedAudioSession) {
+  RTCAudioSessionTest *test = [[RTCAudioSessionTest alloc] init];
+  [test testInterruptedAudioSession];
+}
+
 }  // namespace webrtc