Add more unit tests for JS bindings to Core

mojo/public/bindings/js/test/run_all_unittests.cc

Index: mojo/public/bindings/js/test/run_all_unittests.cc
diff --git a/gin/test/run_all_unittests.cc b/mojo/public/bindings/js/test/run_all_unittests.cc
similarity index 89%
copy from gin/test/run_all_unittests.cc
copy to mojo/public/bindings/js/test/run_all_unittests.cc
index c8644ed3ed6c9a5a5d38674aa4cf1eb716df58fe..a6e4ef6154a1230710243b7dcf6fcb28632eb406 100644
--- a/gin/test/run_all_unittests.cc
+++ b/mojo/public/bindings/js/test/run_all_unittests.cc
@@ -8,11 +8,13 @@
 #include "base/test/launcher/unit_test_launcher.h"
 #include "base/test/test_suite.h"
 #include "gin/initialize.h"
+#include "mojo/system/core_impl.h"
 
 int main(int argc, char** argv) {
   base::TestSuite test_suite(argc, argv);
 
   gin::Initialize();
+  mojo::system::CoreImpl::Init();
 
   return base::LaunchUnitTests(
       argc, argv, base::Bind(&base::TestSuite::Run,