file_manager: Move non-binding code to c/b/chromeos/file_manager

chrome/browser/chromeos/extensions/file_manager/mime_util.cc

-// Copyright 2013 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 "chrome/browser/chromeos/extensions/file_manager/mime_util.h"
-
-#include <utility>
-#include "base/files/file_path.h"
-#include "base/strings/string_util.h"
-#include "net/base/mime_util.h"
-
-namespace file_manager {
-namespace util {
-
-std::string GetMimeTypeForPath(const base::FilePath& file_path) {
-  const base::FilePath::StringType file_extension =
-      StringToLowerASCII(file_path.Extension());
-
-  // TODO(thorogood): Rearchitect this call so it can run on the File thread;
-  // GetMimeTypeFromFile requires this on Linux. Right now, we use
-  // Chrome-level knowledge only.
-  std::string mime_type;
-  if (file_extension.empty() ||
-      !net::GetWellKnownMimeTypeFromExtension(file_extension.substr(1),
-                                              &mime_type)) {
-    // If the file doesn't have an extension or its mime-type cannot be
-    // determined, then indicate that it has the empty mime-type. This will
-    // only be matched if the Web Intents accepts "*" or "*/*".
-    return "";
-  } else {
-    return mime_type;
-  }
-}
-
-}  // namespace util
-}  // namespace file_manager