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

net/tools/net_watcher/net_watcher.cc

Index: net/tools/net_watcher/net_watcher.cc
diff --git a/net/tools/net_watcher/net_watcher.cc b/net/tools/net_watcher/net_watcher.cc
index 9f07513c655ff31900dfe6bd01b36f4bd7273f44..d1ffe4ae745b59b4c64426dcc6527d1b3d4340ae 100644
--- a/net/tools/net_watcher/net_watcher.cc
+++ b/net/tools/net_watcher/net_watcher.cc
@@ -5,6 +5,7 @@
 // This is a small utility that watches for and logs network changes.
 
 #include <string>
+#include <unordered_set>
 
 #include "base/at_exit.h"
 #include "base/command_line.h"
@@ -168,7 +169,7 @@ int main(int argc, char* argv[]) {
   base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
   std::string ignored_netifs_str =
       command_line->GetSwitchValueASCII(kIgnoreNetifFlag);
-  base::hash_set<std::string> ignored_interfaces;
+  std::unordered_set<std::string> ignored_interfaces;
   if (!ignored_netifs_str.empty()) {
     for (const std::string& ignored_netif :
          base::SplitString(ignored_netifs_str, ",", base::TRIM_WHITESPACE,