Have media gallery (through native media file util) use MIME sniffer

webkit/fileapi/media/native_media_file_util.h

Index: webkit/fileapi/media/native_media_file_util.h
diff --git a/webkit/fileapi/media/native_media_file_util.h b/webkit/fileapi/media/native_media_file_util.h
index 0b957c3f28b94aae5ce6bba3e116fd8e169dd207..2357c22230bfa14a1c5b432e2cbfd91586b8ea4a 100644
--- a/webkit/fileapi/media/native_media_file_util.h
+++ b/webkit/fileapi/media/native_media_file_util.h
@@ -57,6 +57,17 @@ class WEBKIT_STORAGE_EXPORT_PRIVATE NativeMediaFileUtil
       const FileSystemURL& url,
       base::PlatformFileInfo* file_info,
       base::FilePath* platform_path) OVERRIDE;
+  virtual base::PlatformFileError CreateSnapshotFile(
+      FileSystemOperationContext* context,
+      const FileSystemURL& url,
+      base::PlatformFileInfo* file_info,
+      base::FilePath* platform_path,
+      SnapshotFilePolicy* snapshot_policy) OVERRIDE;
+
+  // Uses the MIME sniffer code, which actually looks into the file,
+  // to determine if it is really a media file (to avoid exposing
+  // non-media files with a media file extension.)
+  static base::PlatformFileError IsMediaFile(const base::FilePath& path);
 
  private:
   // Like GetLocalFilePath(), but always take media_path_filter() into