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..1da71602637bb4d4f8de821af078f0f0063449e7 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 {
@@ -71,6 +72,17 @@ class MultiprocessTestHelper {
       test_child_name##TestChildMain,                      \
       ::mojo::test::MultiprocessTestHelper::ChildSetup)
 
+// On android, multi-process tests cannot call exec. It means that the test must
+// shutdown the embedder on the forked process as it expects to be in a clean
+// state.
+#if defined(OS_ANDROID)
+#define SHUTDOWN_EMBEDDER_ON_ANDROID() embedder::test::Shutdown()
+#else
+#define SHUTDOWN_EMBEDDER_ON_ANDROID() \
+  do {                                 \
+  } while (0)
+#endif
+
 // Use this (and |WaitForChildTestShutdown()|) for the child process's "main()",
 // 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
@@ -78,6 +90,7 @@ class MultiprocessTestHelper {
 #define MOJO_MULTIPROCESS_TEST_CHILD_TEST(test_child_name) \
   void test_child_name##TestChildTest();                   \
   MOJO_MULTIPROCESS_TEST_CHILD_MAIN(test_child_name) {     \
+    SHUTDOWN_EMBEDDER_ON_ANDROID();                        \
     test_child_name##TestChildTest();                      \
     return (::testing::Test::HasFatalFailure() ||          \
             ::testing::Test::HasNonfatalFailure())         \