Mojo: Add an extremely skeletal mojo_shell_tests.

mojo/mojo.gyp

Index: mojo/mojo.gyp
diff --git a/mojo/mojo.gyp b/mojo/mojo.gyp
index 0d0c059f242664b07a05b7f14c8ed882a91a74b5..c991fa54cd7d75b2ea4e084d4efb197e74a2b7d9 100644
--- a/mojo/mojo.gyp
+++ b/mojo/mojo.gyp
@@ -51,6 +51,7 @@
         'mojo_service_manager_unittests',
         'mojo_shell',
         'mojo_shell_lib',
+        'mojo_shell_tests',
         'mojo_system',
         'mojo_system_impl',
         'mojo_system_unittests',
@@ -575,6 +576,29 @@
       ],
     },
     {
+      'target_name': 'mojo_shell_tests',
+      'type': 'executable',
+      'dependencies': [
+        '../base/base.gyp:base',
+        '../base/base.gyp:test_support_base',
+        '../testing/gtest.gyp:gtest',
+        # TODO(vtl): We don't currently need this, but I imagine we will soon.
+        # '../ui/gl/gl.gyp:gl',
+        '../url/url.gyp:url_lib',
+        'mojo_common_lib',
+        'mojo_environment_chromium',
+        'mojo_service_manager',
+        'mojo_shell_lib',
+        'mojo_system_impl',
+      ],
+      'sources': [
+        'shell/child_process_host_unittest.cc',
+        'shell/shell_test_base.cc',
+        'shell/shell_test_base.h',
+        'shell/shell_test_main.cc',
+      ],
+    },
+    {
       'target_name': 'mojo_service_manager_unittests',
       'type': 'executable',
       'dependencies': [