Change FileStream to use FilePath instead of wstring.

net/base/file_stream_win.cc

 // Copyright (c) 2008 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.
 
 #include "net/base/file_stream.h"
 
 #include <windows.h>
 
 #include "base/logging.h"
 #include "base/message_loop.h"
@@ skipping 107 matching lines @@
   if (file_ != INVALID_HANDLE_VALUE)
     CancelIo(file_);
 
   async_context_.reset();
   if (file_ != INVALID_HANDLE_VALUE) {
     CloseHandle(file_);
     file_ = INVALID_HANDLE_VALUE;
   }
 }
 
-int FileStream::Open(const std::wstring& path, int open_flags) {
+int FileStream::Open(const FilePath& path, int open_flags) {
   if (IsOpen()) {
     DLOG(FATAL) << "File is already open!";
     return ERR_UNEXPECTED;
   }
 
   open_flags_ = open_flags;
-  file_ = base::CreatePlatformFile(path, open_flags_, NULL);
+  file_ = base::CreatePlatformFile(path.value(), open_flags_, NULL);
   if (file_ == INVALID_HANDLE_VALUE) {
     DWORD error = GetLastError();
     LOG(WARNING) << "Failed to open file: " << error;
     return MapErrorCode(error);
   }
 
   if (open_flags_ & base::PLATFORM_FILE_ASYNC) {
     async_context_.reset(new AsyncContext(this));
     MessageLoopForIO::current()->RegisterIOHandler(file_,
                                                    async_context_.get());
@@ skipping 104 matching lines @@
     async_context_->IOCompletionIsPending(callback);
     rv = ERR_IO_PENDING;
   } else {
     rv = static_cast<int>(bytes_written);
   }
   return rv;
 }
 
 }  // namespace net