Minor ObjC header updates.

webrtc/build/ios/export_headers

Index: webrtc/build/ios/export_headers
diff --git a/webrtc/build/ios/export_headers b/webrtc/build/ios/export_headers
index 6808e67e14772429d27738d3a11f6a9176d64e37..84e738c0504a38fc390a04d303b1138ab0b82f8e 100755
--- a/webrtc/build/ios/export_headers
+++ b/webrtc/build/ios/export_headers
@@ -18,16 +18,20 @@ import shutil
 import sys
 
 LEGACY_HEADER_DIRS = ['talk/app/webrtc/objc/public', 'webrtc/base/objc/']
-HEADER_DIRS = ['webrtc/api/objc/', 'webrtc/base/objc/']
+HEADER_DIRS = ['webrtc/api/objc/', 'webrtc/base/objc/',
+               'webrtc/modules/audio_device/ios/objc']
 # Individual header files that should also be exported.
 LEGACY_HEADER_INCLUDES = []
 HEADER_INCLUDES = []
 # Individual header files that should not be exported.
 LEGACY_HEADER_EXCLUDES = ['talk/app/webrtc/objc/public/RTCNSGLVideoView.h']
-HEADER_EXCLUDES = ['webrtc/api/objc/avfoundationvideocapturer.h',
-                   'webrtc/api/objc/RTCNSGLVideoView.h',
-                   'webrtc/base/objc/NSString+StdString.h',
-                   'webrtc/base/objc/RTCUIApplication.h',]
+HEADER_EXCLUDES = [
+  'webrtc/api/objc/avfoundationvideocapturer.h',
+  'webrtc/api/objc/RTCNSGLVideoView.h',
+  'webrtc/base/objc/NSString+StdString.h',
+  'webrtc/base/objc/RTCUIApplication.h',
+  'webrtc/modules/audio_device/ios/objc/RTCAudioSessionDelegateAdapter.h',
+]
 
 def ExportHeaders(include_base_dir, use_legacy_headers):
   """Exports iOS header files.
@@ -41,6 +45,9 @@ def ExportHeaders(include_base_dir, use_legacy_headers):
 
   include_dir_name = 'include'
   include_path = os.path.join(include_base_dir, include_dir_name)
+  # Remove existing directory first in case files change.
+  if (os.path.exists(include_path)):
+    shutil.rmtree(include_path)
 
   script_path = sys.path[0]
   webrtc_base_path = os.path.join(script_path, '../../..')