Adding GlobalFactory class for making registration functions.

Change-Id: I2374c84211a321eba739193f7f7554be43b47cdc
diff --git a/aos/common/util/BUILD b/aos/common/util/BUILD
index b62e93c..4e0455b 100644
--- a/aos/common/util/BUILD
+++ b/aos/common/util/BUILD
@@ -188,6 +188,24 @@
 )
 
 cc_library(
+  name = 'global_factory',
+  hdrs = [
+    'global_factory.h'
+  ],
+)
+
+cc_test(
+  name = 'global_factory_test',
+  srcs = [
+    'global_factory_test.cc'
+  ],
+  deps = [
+    '//aos/testing:googletest',
+    ':global_factory'
+  ],
+)
+
+cc_library(
   name = 'linked_list',
   hdrs = [
     'linked_list.h',