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

[viettrungluu, 2014/11/17 23:56:58]

In general, executing in a forked but not-exec-ed process seems pretty scary and
fragile. Is there any way of avoiding doing this?

[qsr, 2014/11/18 09:55:27]

 Not without a lot of infrastructure work.

 There is no executable to exec. If we wanted this to work, we will have to
modify gtest infrastructure to build application as well as the .so that is run
via jni. Then we will need to bundle the application in the app, and then exec
it. I'm not sure it will even work on a device. Also Android can decide to break
that at any time as they really do not want to have people doing this. And also,
if there is an JNI calls in the exec process, it will miserably fail because
there won't be any Dalvik on it.

 In the end, the real choice we have is doing this (which works, all test are
passing locally), or not run any multi-process tests on Android, which I find a
little bit scary.

+// 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())         \