Add infrastructure to run tests on android.

mojo/edk/test/multiprocess_test_helper.h

Index: mojo/edk/test/multiprocess_test_helper.h
diff --git a/mojo/edk/test/multiprocess_test_helper.h b/mojo/edk/test/multiprocess_test_helper.h
index d131460228aaf69494c9fa3ed23b67cd24a11392..61f43ab35c02f2d13346140025ba0d14e7486ed0 100644
--- a/mojo/edk/test/multiprocess_test_helper.h
+++ b/mojo/edk/test/multiprocess_test_helper.h
@@ -12,6 +12,7 @@
 #include "base/test/multiprocess_test.h"
 #include "base/test/test_timeouts.h"
 #include "mojo/edk/embedder/scoped_platform_handle.h"
+#include "mojo/edk/embedder/test_embedder.h"
 #include "testing/multiprocess_func_list.h"
 
 namespace mojo {
@@ -75,9 +76,12 @@ class MultiprocessTestHelper {
 // if you want to use |EXPECT_...()| or |ASSERT_...()|; it has a |void| return
 // type. (Note that while an |ASSERT_...()| failure will abort the test in the
 // child, it will not abort the test in the parent.)
+// On android, multiprocess cannot exec, so the embedder must be shut down.
 #define MOJO_MULTIPROCESS_TEST_CHILD_TEST(test_child_name) \
   void test_child_name##TestChildTest();                   \
   MOJO_MULTIPROCESS_TEST_CHILD_MAIN(test_child_name) {     \
+    if (embedder::test::IsInitialized())                   \
+      embedder::test::Shutdown();                          \
     test_child_name##TestChildTest();                      \
     return (::testing::Test::HasFatalFailure() ||          \
             ::testing::Test::HasNonfatalFailure())         \