iOS audio session isInterrupted flag does not get reset correctly:

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

Index: webrtc/modules/audio_device/ios/objc/RTCAudioSessionTest.mm
diff --git a/webrtc/modules/audio_device/ios/objc/RTCAudioSessionTest.mm b/webrtc/modules/audio_device/ios/objc/RTCAudioSessionTest.mm
index a4b49fc1c08129fb4f3f2a1ba0b12397769a9b87..1793e01610be1e2dd72a34b881c7328638b2eb39 100644
--- a/webrtc/modules/audio_device/ios/objc/RTCAudioSessionTest.mm
+++ b/webrtc/modules/audio_device/ios/objc/RTCAudioSessionTest.mm
@@ -11,6 +11,9 @@
 #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"
@@ -246,6 +249,35 @@ OCMLocation *OCMMakeLocation(id testCase, const char *fileCString, int line){
   [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 {
@@ -295,4 +327,9 @@ TEST_F(AudioSessionTest, ConfigureWebRTCSession) {
   [test testConfigureWebRTCSession];
 }
 
+TEST_F(AudioSessionTest, testInterruptedAudioSession) {
+  RTCAudioSessionTest *test = [[RTCAudioSessionTest alloc] init];
+  [test testInterruptedAudioSession];
+}
+
 }  // namespace webrtc