Avoid disk accesses on the wrong thread in URLRequestFileJob

net/url_request/url_request_file_job.h

Index: net/url_request/url_request_file_job.h
===================================================================
--- net/url_request/url_request_file_job.h	(revision 145483)
+++ net/url_request/url_request_file_job.h	(working copy)
@@ -10,6 +10,7 @@
 #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"
@@ -60,22 +61,26 @@
                                   const FilePath& path);
 
   // Callback after fetching file info on a background thread.
-  void DidResolve(bool exists, const base::PlatformFileInfo& file_info);
+  void DidResolve(const bool* exists, const base::PlatformFileInfo* file_info);
 
+  // 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_;
+  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);
 };