Experimental patch for delaying mic permission dialog in AppRTCMobile

webrtc/modules/audio_device/ios/voice_processing_audio_unit.mm

Index: webrtc/modules/audio_device/ios/voice_processing_audio_unit.mm
diff --git a/webrtc/modules/audio_device/ios/voice_processing_audio_unit.mm b/webrtc/modules/audio_device/ios/voice_processing_audio_unit.mm
index 3701f3fee367d383be690fdad1c6effad6a20b0c..3427fbf636e2bca0397bb5c73ca2bb5bf56dee47 100644
--- a/webrtc/modules/audio_device/ios/voice_processing_audio_unit.mm
+++ b/webrtc/modules/audio_device/ios/voice_processing_audio_unit.mm
@@ -84,6 +84,7 @@ const UInt32 VoiceProcessingAudioUnit::kBytesPerSample = 2;
 
 bool VoiceProcessingAudioUnit::Init() {
   RTC_DCHECK_EQ(state_, kInitRequired);
+  RTCLog(@"Init");
 
   // Create an audio component description to identify the Voice Processing
   // I/O audio unit.
@@ -107,19 +108,6 @@ bool VoiceProcessingAudioUnit::Init() {
     return false;
   }
 
-  // Enable input on the input scope of the input element.
-  UInt32 enable_input = 1;
-  result = AudioUnitSetProperty(vpio_unit_, kAudioOutputUnitProperty_EnableIO,
-                                kAudioUnitScope_Input, kInputBus, &enable_input,
-                                sizeof(enable_input));
-  if (result != noErr) {
-    DisposeAudioUnit();
-    RTCLogError(@"Failed to enable input on input scope of input element. "
-                 "Error=%ld.",
-                (long)result);
-    return false;
-  }
-
   // Enable output on the output scope of the output element.
   UInt32 enable_output = 1;
   result = AudioUnitSetProperty(vpio_unit_, kAudioOutputUnitProperty_EnableIO,
@@ -194,6 +182,20 @@ bool VoiceProcessingAudioUnit::Initialize(Float64 sample_rate) {
   RTCLog(@"Initializing audio unit with sample rate: %f", sample_rate);
 
   OSStatus result = noErr;
+
+  // Enable input on the input scope of the input element.
+  UInt32 enable_input = 1;
+  result = AudioUnitSetProperty(vpio_unit_, kAudioOutputUnitProperty_EnableIO,
+                                kAudioUnitScope_Input, kInputBus, &enable_input,
+                                sizeof(enable_input));
+  if (result != noErr) {
+    DisposeAudioUnit();
+    RTCLogError(@"Failed to enable input on input scope of input element. "
+                 "Error=%ld.",
+                (long)result);
+    return false;
+  }
+
   AudioStreamBasicDescription format = GetFormat(sample_rate);
   UInt32 size = sizeof(format);
 #if !defined(NDEBUG)