Improves EXPECT_DEATH_IF_SUPPORTED to allow streaming of messages and enforcing the validity of arguments (by Vlad Losev); adds samples for the event listener API (by Vlad Losev); simplifies the tests using EXPECT_DEATH_IF_SUPPORTED (by Zhanyong Wan).

test/gtest-port_test.cc

@@ -133,8 +133,6 @@ TEST(GetThreadCountTest, ReturnsZeroWhenUnableToCountThreads) {
 }
 #endif  // GTEST_OS_MAC
 
-#if GTEST_HAS_DEATH_TEST
-
 TEST(GtestCheckDeathTest, DiesWithCorrectOutputOnFailure) {
   const bool a_false_condition = false;
   const char regex[] =
@@ -145,9 +143,12 @@ TEST(GtestCheckDeathTest, DiesWithCorrectOutputOnFailure) {
 #endif  // _MSC_VER
      ".*a_false_condition.*Extra info.*";
 
-  EXPECT_DEATH(GTEST_CHECK_(a_false_condition) << "Extra info", regex);
+  EXPECT_DEATH_IF_SUPPORTED(GTEST_CHECK_(a_false_condition) << "Extra info",
+                            regex);
 }
 
+#if GTEST_HAS_DEATH_TEST
+
 TEST(GtestCheckDeathTest, LivesSilentlyOnSuccess) {
   EXPECT_EXIT({
       GTEST_CHECK_(true) << "Extra info";