Avoid disk accesses on the wrong thread in URLRequestFileJob

net/url_request/url_request_file_job.h

 // Copyright (c) 2012 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 NET_URL_REQUEST_URL_REQUEST_FILE_JOB_H_
 #define NET_URL_REQUEST_URL_REQUEST_FILE_JOB_H_
 #pragma once
 
 #include <string>
 #include <vector>
 
 #include "base/file_path.h"
+#include "base/memory/weak_ptr.h"
 #include "net/base/file_stream.h"
 #include "net/base/net_export.h"
 #include "net/http/http_byte_range.h"
 #include "net/url_request/url_request.h"
 #include "net/url_request/url_request_job.h"
 
 namespace file_util {
 struct FileInfo;
 }
 
@@ skipping 30 matching lines @@
   FilePath file_path_;
 
  private:
   // Tests to see if access to |path| is allowed. If g_allow_file_access_ is
   // true, then this will return true. If the NetworkDelegate associated with
   // the |request| says it's OK, then this will also return true.
   static bool IsFileAccessAllowed(const URLRequest& request,
                                   const FilePath& path);
 
   // Callback after fetching file info on a background thread.
-  void DidResolve(bool exists, const base::PlatformFileInfo& file_info);
+  void DidResolveAndMimeType(const bool* exists,
+                             const base::PlatformFileInfo* file_info,
+                             const bool* mime_type_result,
+                             const std::string* read_mime_type);
+
+  // Callback after opening file on a background thread.
+  void DidOpen(int result);
+
+  // Callback after seeking to necessary position in the file which is done
+  // on a background thread.
+  void DidSeek(int64 result);
 
   // Callback after data is asynchronously read from the file.
   void DidRead(int result);
 
   FileStream stream_;
   bool is_directory_;
+  bool mime_type_result_;
+  std::string mime_type_;
+  int64 file_size_;
 
   HttpByteRange byte_range_;
   int64 remaining_bytes_;
 
-  // The initial file metadata is fetched on a background thread.
-  // AsyncResolver runs that task.
-  class AsyncResolver;
-  friend class AsyncResolver;
-  scoped_refptr<AsyncResolver> async_resolver_;
+  base::WeakPtrFactory<URLRequestFileJob> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(URLRequestFileJob);
 };
 
 }  // namespace net
 
 #endif  // NET_URL_REQUEST_URL_REQUEST_FILE_JOB_H_