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

webkit/fileapi/media/device_media_async_file_util.h

Index: webkit/fileapi/media/device_media_async_file_util.h
diff --git a/webkit/fileapi/media/device_media_async_file_util.h b/webkit/fileapi/media/device_media_async_file_util.h
index 2b04329abc66047a0bc5191598eb1df8621634d3..39ec33d923c72cbe1867839b1942a765adc1ab99 100644
--- a/webkit/fileapi/media/device_media_async_file_util.h
+++ b/webkit/fileapi/media/device_media_async_file_util.h
@@ -138,13 +138,22 @@ class WEBKIT_STORAGE_EXPORT_PRIVATE DeviceMediaAsyncFileUtil
 
   // Called when the snapshot file specified by the |platform_path| is
   // successfully created. |file_info| contains the device media file details
-  // for which the snapshot file is created. |callback| is invoked to complete
-  // the CreateSnapshotFile request.
+  // for which the snapshot file is created.
   void OnDidCreateSnapshotFile(
+      FileSystemOperationContext* context,
       const AsyncFileUtil::CreateSnapshotFileCallback& callback,
       const base::PlatformFileInfo& file_info,
       const base::FilePath& platform_path);
 
+  // Called after OnDidCreateSnapshotFile finishes media check.
+  // |callback| is invoked to complete the CreateSnapshotFile request.
+  // It is called with |*error| regardless of result.
+  void OnDidCheckMediaRunTask(
+      const AsyncFileUtil::CreateSnapshotFileCallback& callback,
+      const base::PlatformFileInfo& file_info,
+      const base::FilePath& platform_path,
+      base::PlatformFileError* error);
+
   // Called when CreateSnapshotFile method call fails. |callback| is invoked to
   // notify the caller about the |error|.
   void OnCreateSnapshotFileError(