Remove stale references to PlatformFile flags, errors or functions.

chrome/browser/media_galleries/fileapi/safe_audio_video_checker.h

Index: chrome/browser/media_galleries/fileapi/safe_audio_video_checker.h
diff --git a/chrome/browser/media_galleries/fileapi/safe_audio_video_checker.h b/chrome/browser/media_galleries/fileapi/safe_audio_video_checker.h
index 94e611fa2e617c8cfa59a23b52995e6541bfed46..c791e6ed0093621381c2963492f2b110e2986a5f 100644
--- a/chrome/browser/media_galleries/fileapi/safe_audio_video_checker.h
+++ b/chrome/browser/media_galleries/fileapi/safe_audio_video_checker.h
@@ -17,7 +17,7 @@ class UtilityProcessHost;
 }
 
 // Uses a utility process to validate a media file.  If the callback returns
-// PLATFORM_FILE_OK, then the file appears to be a valid media file. This does
+// File::FILE_OK, then the file appears to be a valid media file. This does
 // not attempt to decode the entire file, which may take a considerable amount
 // of time.  This class may be constructed on any thread, but should run on the
 // IO thread.