Reland 'Convert //net and //chromecast to std::unordered_*'

net/base/platform_mime_util_win.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 "net/base/platform_mime_util.h"
 
 #include <string>
 
 #include "base/strings/utf_string_conversions.h"
 #include "base/win/registry.h"
@@ skipping 24 matching lines @@
   }
   // Strip off the leading dot, this should always be the case.
   if (!ext->empty() && ext->at(0) == L'.')
     ext->erase(ext->begin());
 
   return true;
 }
 
 void PlatformMimeUtil::GetPlatformExtensionsForMimeType(
     const std::string& mime_type,
-    base::hash_set<base::FilePath::StringType>* extensions) const {
+    std::unordered_set<base::FilePath::StringType>* extensions) const {
   // Multiple extensions could have the given mime type specified as their types
   // in their 'HKCR\.<extension>\Content Type' keys. Iterating all the HKCR
   // entries, though, is wildly impractical. Cheat by returning just the
   // preferred extension.
   base::FilePath::StringType ext;
   if (GetPreferredExtensionForMimeType(mime_type, &ext))
     extensions->insert(ext);
 }
 
 }  // namespace net