Use a direct include of utf_string_conversions.h in android_webview/, apps/, ash/, base/.

base/platform_file_posix.cc

 // 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.
 
 #include "base/platform_file.h"
 
 #include <fcntl.h>
 #include <errno.h>
 #include <sys/stat.h>
 #include <unistd.h>
 
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/metrics/sparse_histogram.h"
 #include "base/posix/eintr_wrapper.h"
+#include "base/strings/utf_string_conversions.h"
 #include "base/threading/thread_restrictions.h"
-#include "base/utf_string_conversions.h"
 
 #if defined(OS_ANDROID)
 #include "base/os_compat_android.h"
 #endif
 
 namespace base {
 
 // Make sure our Whence mappings match the system headers.
 COMPILE_ASSERT(PLATFORM_FILE_FROM_BEGIN   == SEEK_SET &&
                PLATFORM_FILE_FROM_CURRENT == SEEK_CUR &&
@@ skipping 301 matching lines @@
     default:
 #if !defined(OS_NACL)  // NaCl build has no metrics code.
       UMA_HISTOGRAM_SPARSE_SLOWLY("PlatformFile.UnknownErrors.Posix",
                                   saved_errno);
 #endif
       return PLATFORM_FILE_ERROR_FAILED;
   }
 }
 
 }  // namespace base