Replace uses of hash_map in //base

base/tracked_objects.h

Index: base/tracked_objects.h
diff --git a/base/tracked_objects.h b/base/tracked_objects.h
index 36caec3c6e45ea0984cba1bfa8551c4c7f1af565..d246cfd82b3df3cf930134fe6cc9cae46092674b 100644
--- a/base/tracked_objects.h
+++ b/base/tracked_objects.h
@@ -11,6 +11,7 @@
 #include <set>
 #include <stack>
 #include <string>
+#include <unordered_map>
 #include <utility>
 #include <vector>
 
@@ -522,7 +523,7 @@ class BASE_EXPORT ThreadData {
     STATUS_LAST = PROFILING_ACTIVE
   };
 
-  typedef base::hash_map<Location, Births*, Location::Hash> BirthMap;
+  typedef std::unordered_map<Location, Births*, Location::Hash> BirthMap;
   typedef std::map<const Births*, DeathData> DeathMap;
 
   // Initialize the current thread context with a new instance of ThreadData.