Make unit tests build and run on Chrome OS.

Bug: 34520446
Test: Builds on desktop Linux, Android, Chrome OS.
Change-Id: Icb14aa4f6bd15950d082fc78bc4b28095e0b0af0
diff --git a/Makefile b/Makefile
index b9e7ad8..48d9f9d 100644
--- a/Makefile
+++ b/Makefile
@@ -16,17 +16,17 @@
 CPPFLAGS += -DUSE_SECCOMP_SOFTFAIL
 endif
 
-CFLAGS += -Wextra
-CXXFLAGS += -Wextra
+CFLAGS += -Wextra -Wno-missing-field-initializers
+CXXFLAGS += -Wextra -Wno-missing-field-initializers
 
 USE_SYSTEM_GTEST ?= no
 ifeq ($(USE_SYSTEM_GTEST),no)
-GTEST_CXXFLAGS :=
+GTEST_CXXFLAGS := -std=gnu++11
 GTEST_MAIN := gtest_main.a
 GTEST_LIBS := gtest.a
 else
 GTEST_CXXFLAGS := $(gtest-config --cxxflags)
-GTEST_MAIN := -lgtest_main
+GTEST_MAIN := -lgtest -lgtest_main
 GTEST_LIBS := $(gtest-config --libs)
 endif
 
@@ -35,8 +35,8 @@
 
 parse_seccomp_policy: CXX_BINARY(parse_seccomp_policy)
 
-# TODO(jorgelo): convert to TEST().
-tests: CXX_BINARY(libminijail_unittest) CXX_BINARY(syscall_filter_unittest)
+tests: TEST(CXX_BINARY(libminijail_unittest)) \
+	TEST(CXX_BINARY(syscall_filter_unittest))
 
 
 CC_BINARY(minijail0): LDLIBS += -lcap -ldl
@@ -132,7 +132,7 @@
 CPPFLAGS += -isystem $(GTEST_DIR)/include
 
 # Flags passed to the C++ compiler.
-GTEST_CXXFLAGS := -pthread
+GTEST_CXXFLAGS += -pthread
 
 # All Google Test headers.  Usually you shouldn't change this
 # definition.