Compile and install most of the googletest examples

sample9_unittest is not compiled/installed, because it intentionally fails
and would result in red test runs until broken to always pass.

etc/mtree/BSD.tests.dist

@@ -440,6 +440,8 @@
             tests
                 atf
                 ..
+                googletest
+                ..
                 plain
                 ..
                 tap

share/examples/tests/tests/Makefile

@@ -1,5 +1,7 @@
 # $FreeBSD$
 
+.include <src.opts.mk>
+
 # Directory into which the Kyuafile provided by this directory will be
 # installed.
 #
@@ -21,6 +23,10 @@ TESTS_SUBDIRS+=	atf
 TESTS_SUBDIRS+=	plain
 TESTS_SUBDIRS+=	tap
 
+.if ${MK_GOOGLETEST} != no
+TESTS_SUBDIRS+= googletest
+.endif
+
 # We leave KYUAFILE unset so that bsd.test.mk auto-generates a Kyuafile
 # for us based on the contents of the TESTS_SUBDIRS line above.  The
 # generated file will tell the tests run-time engine to recurse into the

share/examples/tests/tests/googletest/Makefile

@@ -0,0 +1,36 @@
+# $FreeBSD$
+
+.PATH: ${SRCTOP}/contrib/googletest/googletest/samples
+
+GTEST_MAIN_REQ_TESTS+=	sample1_unittest
+GTEST_MAIN_REQ_TESTS+=	sample2_unittest
+GTEST_MAIN_REQ_TESTS+=	sample3_unittest
+GTEST_MAIN_REQ_TESTS+=	sample4_unittest
+GTEST_MAIN_REQ_TESTS+=	sample5_unittest
+GTEST_MAIN_REQ_TESTS+=	sample6_unittest
+GTEST_MAIN_REQ_TESTS+=	sample7_unittest
+GTEST_MAIN_REQ_TESTS+=	sample8_unittest
+
+# sample9_unittest's `CustomOutputTest.Fails` fails intentionally to illustrate
+# how output format can be adjusted with command-line parameters.
+#GTEST_REQ_TESTS+=	sample9_unittest
+GTEST_REQ_TESTS+=	sample10_unittest
+
+.for t in ${GTEST_MAIN_REQ_TESTS}
+GTESTS+=	$t
+LIBADD.$t+=	gtest_main
+SRCS.$t+=	$t.cc
+.endfor
+
+.for t in ${GTEST_REQ_TESTS}
+GTESTS+=	$t
+LIBADD.$t+=	gtest
+SRCS.$t+=	$t.cc
+.endfor
+
+SRCS.sample1_unittest+=	sample1.cc
+SRCS.sample2_unittest+=	sample2.cc
+SRCS.sample4_unittest+=	sample4.cc
+SRCS.sample5_unittest+=	sample1.cc
+
+.include <bsd.test.mk>