Allow host valgrind gtests to be run individually.

Change-Id: I80976600034046cb42e8565bfd38f75811d7a08e
diff --git a/Android.mk b/Android.mk
index 8024a3d..bf2eb9a 100644
--- a/Android.mk
+++ b/Android.mk
@@ -146,14 +146,9 @@
 test-art-host-gtest: $(ART_HOST_TEST_TARGETS)
 	@echo test-art-host-gtest PASSED
 
-define run-host-gtests-with
-  $(foreach file,$(sort $(ART_HOST_TEST_EXECUTABLES)),$(1) $(file) &&) true
-endef
-
 # "mm valgrind-test-art-host-gtest" to build and run the host gtests under valgrind.
 .PHONY: valgrind-test-art-host-gtest
-valgrind-test-art-host-gtest: test-art-host-dependencies
-	$(call run-host-gtests-with,valgrind --leak-check=full)
+valgrind-test-art-host-gtest: $(ART_HOST_VALGRIND_TEST_TARGETS)
 	@echo valgrind-test-art-host-gtest PASSED
 
 .PHONY: test-art-host-oat-default
diff --git a/build/Android.gtest.mk b/build/Android.gtest.mk
index 655c7dd..8165ec7 100644
--- a/build/Android.gtest.mk
+++ b/build/Android.gtest.mk
@@ -170,6 +170,13 @@
 	@echo $$@ PASSED
 
 ART_HOST_TEST_TARGETS += $$(art_gtest_target)
+
+.PHONY: valgrind-$$(art_gtest_target)
+valgrind-$$(art_gtest_target): $$(art_gtest_exe) test-art-host-dependencies
+	valgrind --leak-check=full $$<
+	@echo $$@ PASSED
+
+ART_HOST_VALGRIND_TEST_TARGETS += valgrind-$$(art_gtest_target)
 endif
 endef