Browser-wide audio mirroring for TabCapture API

media/audio/audio_input_controller.cc

Index: media/audio/audio_input_controller.cc
diff --git a/media/audio/audio_input_controller.cc b/media/audio/audio_input_controller.cc
index 99bb420e89553a84e6292a2fa74d404b5eed91eb..2032972f520cfc7c1972b45c58250f95e479b58b 100644
--- a/media/audio/audio_input_controller.cc
+++ b/media/audio/audio_input_controller.cc
@@ -148,10 +148,11 @@ void AudioInputController::DoCreate(AudioManager* audio_manager,
   DCHECK(!no_data_timer_.get());
   // Create the data timer which will call DoCheckForNoData(). The timer
   // is started in DoRecord() and restarted in each DoCheckForNoData() callback.
-  no_data_timer_.reset(new base::Timer(
-      FROM_HERE, base::TimeDelta::FromSeconds(kTimerInitialIntervalSeconds),
-      base::Bind(&AudioInputController::DoCheckForNoData,
-      base::Unretained(this)), false));
+  if (params.format() != AudioParameters::AUDIO_WEB_CONTENTS)
+    no_data_timer_.reset(new base::Timer(
+        FROM_HERE, base::TimeDelta::FromSeconds(kTimerInitialIntervalSeconds),
+        base::Bind(&AudioInputController::DoCheckForNoData,
+        base::Unretained(this)), false));
   state_ = kCreated;
   handler_->OnCreated(this);
 }
@@ -169,7 +170,8 @@ void AudioInputController::DoRecord() {
 
   // Start the data timer. Once |kTimerResetIntervalSeconds| have passed,
   // a callback to DoCheckForNoData() is made.
-  no_data_timer_->Reset();
+  if (no_data_timer_.get())
+    no_data_timer_->Reset();
 
   stream_->Start(this);
   handler_->OnRecording(this);
@@ -250,10 +252,11 @@ void AudioInputController::DoCheckForNoData() {
 
   // Restart the timer to ensure that we check the flag again in
   // |kTimerResetIntervalSeconds|.
-  no_data_timer_->Start(
-      FROM_HERE, base::TimeDelta::FromSeconds(kTimerResetIntervalSeconds),
-      base::Bind(&AudioInputController::DoCheckForNoData,
-      base::Unretained(this)));
+  if (no_data_timer_.get())
+    no_data_timer_->Start(
+        FROM_HERE, base::TimeDelta::FromSeconds(kTimerResetIntervalSeconds),
+        base::Bind(&AudioInputController::DoCheckForNoData,
+        base::Unretained(this)));
 }
 
 void AudioInputController::OnData(AudioInputStream* stream, const uint8* data,