Java API for mojo system.

mojo/mojo_public.gypi

 {
   'targets': [
     {
       'target_name': 'mojo_system',
       'type': 'static_library',
       'defines': [
         'MOJO_SYSTEM_IMPLEMENTATION',
       ],
       'include_dirs': [
         '..',
@@ skipping 332 matching lines @@
         'public/cpp/shell/lib/service.cc',
       ],
       'dependencies': [
         'mojo_shell_bindings',
       ],
       'export_dependent_settings': [
         'mojo_shell_bindings',
       ],
     },
   ],
+  'conditions': [
+    ['OS == "android"', {
+      'targets': [
+        {
+          'target_name': 'mojo_public_java',
+          'type': 'none',
+          'variables': {
+            'java_in_dir': 'public/java',
+          },
+          'includes': [ '../build/java.gypi' ],
+        },
+      ],
+    }],
+  ],
 }