Adds support for detection of running in death test child processes.

include/gtest/gtest-death-test.h

@@ -51,6 +51,17 @@ GTEST_DECLARE_string_(death_test_style);
 
 #if GTEST_HAS_DEATH_TEST
 
+namespace internal {
+
+// Returns a Boolean value indicating whether the caller is currently
+// executing in the context of the death test child process.  Tools such as
+// Valgrind heap checkers may need this to modify their behavior in death
+// tests.  IMPORTANT: This is an internal utility.  Using it may break the
+// implementation of death tests.  User code MUST NOT use it.
+GTEST_API_ bool InDeathTestChild();
+
+}  // namespace internal
+
 // The following macros are useful for writing death tests.
 
 // Here's what happens when an ASSERT_DEATH* or EXPECT_DEATH* is