Reland "Enable libc++ on Android"

third_party/re2/util/util.h

 // Copyright 2009 The RE2 Authors.  All Rights Reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 #ifndef RE2_UTIL_UTIL_H__
 #define RE2_UTIL_UTIL_H__
 
 // C
 #include <stdio.h>
 #include <string.h>
@@ skipping 36 matching lines @@
 using std::make_pair;
 
 #if defined(__GNUC__) && !defined(USE_CXX0X) && !defined(_LIBCPP_ABI_VERSION) && !defined(OS_ANDROID)
 
 #include <tr1/unordered_set>
 using std::tr1::unordered_set;
 
 #else
 
 #include <unordered_set>
-#if defined(WIN32) || defined(OS_ANDROID)
+#if defined(WIN32) || (defined(OS_ANDROID) && !defined(_LIBCPP_ABI_VERSION))
 using std::tr1::unordered_set;
 #else
 using std::unordered_set;
 #endif
 
 #endif
 
 namespace re2 {
 
 typedef int8_t int8;
@@ skipping 73 matching lines @@
 }
 
 }  // namespace re2
 
 #include "util/arena.h"
 #include "util/logging.h"
 #include "util/mutex.h"
 #include "util/utf.h"
 
 #endif // RE2_UTIL_UTIL_H__