[Coverity] Fixed call by value to by reference

content/browser/renderer_host/redirect_to_file_resource_handler.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 CONTENT_BROWSER_RENDERER_HOST_REDIRECT_TO_FILE_RESOURCE_HANDLER_H_
 #define CONTENT_BROWSER_RENDERER_HOST_REDIRECT_TO_FILE_RESOURCE_HANDLER_H_
 
 #include "base/file_path.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 38 matching lines @@
                                int* bytes_read) OVERRIDE;
   virtual bool OnResponseCompleted(int request_id,
                                    const net::URLRequestStatus& status,
                                    const std::string& security_info) OVERRIDE;
   virtual void OnRequestClosed() OVERRIDE;
 
  private:
   virtual ~RedirectToFileResourceHandler();
   void DidCreateTemporaryFile(base::PlatformFileError error_code,
                               base::PassPlatformFile file_handle,
-                              FilePath file_path);
+                              const FilePath& file_path);
   void DidWriteToFile(int result);
   bool WriteMore();
   bool BufIsFull() const;
 
   base::WeakPtrFactory<RedirectToFileResourceHandler> weak_factory_;
 
   ResourceDispatcherHost* host_;
   int process_id_;
   int request_id_;
 
@@ skipping 21 matching lines @@
   bool completed_during_write_;
   net::URLRequestStatus completed_status_;
   std::string completed_security_info_;
 
   DISALLOW_COPY_AND_ASSIGN(RedirectToFileResourceHandler);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_REDIRECT_TO_FILE_RESOURCE_HANDLER_H_