Add operating system detection for Chrome OS

src/parser-os.js

@@ -144,4 +144,14 @@ export default [
       };
     },
   },
+
+  /* Chrome OS */
+  {
+    test: [/CrOS/],
+    describe() {
+      return {
+        name: 'Chrome OS',
+      };
+    },
+  },
 ];

test/acceptance/useragentstrings.yml

@@ -174,7 +174,8 @@
         browser:
           name: "Chrome"
           version: "29.0.1547.57"
-        os: {}
+        os:
+          name: "Chrome OS"
         platform: {}
         engine:
           name: "Blink"