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

chrome/browser/media_galleries/fileapi/device_media_async_file_util.h

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_MEDIA_GALLERIES_FILEAPI_DEVICE_MEDIA_ASYNC_FILE_UTIL_H_
 #define CHROME_BROWSER_MEDIA_GALLERIES_FILEAPI_DEVICE_MEDIA_ASYNC_FILE_UTIL_H_
 
 #include "base/files/file_path.h"
 #include "base/memory/weak_ptr.h"
 #include "base/platform_file.h"
+#include "webkit/blob/shareable_file_reference.h"
 #include "webkit/fileapi/async_file_util.h"
 
 namespace base {
 class SequencedTaskRunner;
 class Time;
 }
 
 namespace fileapi {
 class FileSystemOperationContext;
 class FileSystemURL;
@@ skipping 111 matching lines @@
 
   // Called when ReadDirectory method call failed to enumerate the directory
   // objects. |callback| is invoked to notify the caller about the |error|
   // that occured while reading the directory objects.
   void OnReadDirectoryError(
       const AsyncFileUtil::ReadDirectoryCallback& callback,
       base::PlatformFileError error);
 
   // 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(
       const AsyncFileUtil::CreateSnapshotFileCallback& callback,
       base::SequencedTaskRunner* media_task_runner,
       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 OnDidCheckMedia(
+      const AsyncFileUtil::CreateSnapshotFileCallback& callback,
+      base::SequencedTaskRunner* media_task_runner,
+      const base::PlatformFileInfo& file_info,
+      scoped_refptr<webkit_blob::ShareableFileReference> platform_file,
+      base::PlatformFileError* error);
+
   // Called when CreateSnapshotFile method call fails. |callback| is invoked to
   // notify the caller about the |error|.
   void OnCreateSnapshotFileError(
       const AsyncFileUtil::CreateSnapshotFileCallback& callback,
       base::PlatformFileError error);
 
   // Called when the snapshot file specified by the |snapshot_file_path| is
   // created to hold the contents of the |device_file_path|. If the snapshot
   // file is successfully created, |snapshot_file_path| will be an non-empty
   // file path. In case of failure, |snapshot_file_path| will be an empty file
@@ skipping 10 matching lines @@
 
   // For callbacks that may run after destruction.
   base::WeakPtrFactory<DeviceMediaAsyncFileUtil> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DeviceMediaAsyncFileUtil);
 };
 
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_MEDIA_GALLERIES_FILEAPI_DEVICE_MEDIA_ASYNC_FILE_UTIL_H_