Fix warnings encountered with clang -Wall.

include/gtest/internal/gtest-port.h

@@ -810,8 +810,8 @@ class Secret;
 // expression is true. For example, you could use it to verify the
 // size of a static array:
 //
-//   GTEST_COMPILE_ASSERT_(ARRAYSIZE(content_type_names) == CONTENT_NUM_TYPES,
-//                         content_type_names_incorrect_size);
+//   GTEST_COMPILE_ASSERT_(GTEST_ARRAY_SIZE_(names) == NUM_NAMES,
+//                         names_incorrect_size);
 //
 // or to make sure a struct is smaller than a certain size:
 //
@@ -879,6 +879,9 @@ struct StaticAssertTypeEqHelper;
 template <typename T>
 struct StaticAssertTypeEqHelper<T, T> {};
 
+// Evaluates to the number of elements in 'array'.
+#define GTEST_ARRAY_SIZE_(array) (sizeof(array) / sizeof(array[0]))
+
 #if GTEST_HAS_GLOBAL_STRING
 typedef ::string string;
 #else