Increase filename size for dummy device factory.

Some of our internal clients complained the size was to small
because their paths are very long. This fixes that problem.

BUG=None
R=henrika@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/46839004

Cr-Commit-Position: refs/heads/master@{#8948}
diff --git a/webrtc/modules/audio_device/dummy/file_audio_device_factory.h b/webrtc/modules/audio_device/dummy/file_audio_device_factory.h
index 96cab67..250b7f6 100644
--- a/webrtc/modules/audio_device/dummy/file_audio_device_factory.h
+++ b/webrtc/modules/audio_device/dummy/file_audio_device_factory.h
@@ -31,7 +31,7 @@
                                 const char* outputAudioFilename);
 
  private:
-  static const uint32_t MAX_FILENAME_LEN = 256;
+  static const uint32_t MAX_FILENAME_LEN = 512;
   static bool _isConfigured;
   static char _inputAudioFilename[MAX_FILENAME_LEN];
   static char _outputAudioFilename[MAX_FILENAME_LEN];