clang support

testing/gtest.gyp

Index: testing/gtest.gyp
diff --git a/testing/gtest.gyp b/testing/gtest.gyp
index e813b497930cb9dc8469a2308d89d18726450a35..da95f42e5c612124d19a1f80ba22083a86e755cd 100644
--- a/testing/gtest.gyp
+++ b/testing/gtest.gyp
@@ -79,6 +79,20 @@
             ],
           },
         }],
+        ['clang==1', {
+          # We want gtest features that use tr1::tuple, but clang currently
+          # doesn't support the variadic templates used by libstdc++'s
+          # implementation.  gtest supports this scenario by providing its
+          # own implementation but we must opt in to it.
+          'defines': [
+            'GTEST_USE_OWN_TR1_TUPLE=1',
+          ],
+          'direct_dependent_settings': {
+            'defines': [
+              'GTEST_USE_OWN_TR1_TUPLE=1',
+            ],
+          },
+        }],
       ],
       'direct_dependent_settings': {
         'defines': [