Bug 1529762 - PageStyle child actors should only instantiate for web pages. r=Felipe

This avoids instantiating them for internal pages, like about:home.

Differential Revision: https://phabricator.services.mozilla.com/D22520

--HG--
extra : moz-landing-system : lando

browser/base/content/test/performance/browser_startup_content.js

@@ -46,7 +46,6 @@ const whitelist = {
     "resource:///actors/BrowserTabChild.jsm",
     "resource:///modules/ContentMetaHandler.jsm",
     "resource:///actors/LinkHandlerChild.jsm",
-    "resource:///actors/PageStyleChild.jsm",
     "resource:///actors/SearchTelemetryChild.jsm",
     "resource://gre/modules/ActorChild.jsm",
     "resource://gre/modules/ActorManagerChild.jsm",

browser/components/BrowserGlue.jsm

@@ -215,6 +215,9 @@ let ACTORS = {
         "PageStyle:Switch",
         "PageStyle:Disable",
       ],
+      // Only matching web pages, as opposed to internal about:, chrome: or
+      // resource: pages. See https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/Match_patterns
+      matches: ["*://*/*"],
     },
   },