Bug 1307009 - Remove caching optimization; r=tromey

This caching feature is no longer valid as the client-side database
will not necessarily be the same as the server since the DB is
only built on nightly.

MozReview-Commit-ID: 550EQmgO9O7

devtools/shared/specs/css-properties.js

@@ -3,16 +3,14 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 "use strict";
 
-const { Arg, RetVal, generateActorSpec } = require("devtools/shared/protocol");
+const { RetVal, generateActorSpec } = require("devtools/shared/protocol");
 
 const cssPropertiesSpec = generateActorSpec({
   typeName: "cssProperties",
 
   methods: {
     getCSSDatabase: {
-      request: {
-        clientBrowserVersion: Arg(0, "string"),
-      },
+      request: {},
 
       response: RetVal("json"),
     }