Issue 242 - Use user style sheets on Chromium

lib/cssInjection.js

Index: lib/cssInjection.js
===================================================================
--- a/lib/cssInjection.js
+++ b/lib/cssInjection.js
@@ -21,29 +21,37 @@
 
 const {RegExpFilter} = require("filterClasses");
 const {ElemHide} = require("elemHide");
 const {ElemHideEmulation} = require("elemHideEmulation");
 const {checkWhitelisted} = require("whitelisting");
 const {extractHostFromFrame} = require("url");
 const {port} = require("messaging");
 const devtools = require("devtools");
+const info = require("info");
 
-const userStyleSheetsSupported = "extensionTypes" in browser &&
-                                 "CSSOrigin" in browser.extensionTypes;
+const cssOriginSupported = "extensionTypes" in browser &&
+                           "CSSOrigin" in browser.extensionTypes;
+const userStyleSheetsSupported = cssOriginSupported ||
+                                 (info.platform == "chromium" &&
+                                  parseInt(info.platformVersion, 10) >= 64);
 
 function hideElements(tabId, frameId, selectors)
 {
-  browser.tabs.insertCSS(tabId, {
+  let options = {
     code: selectors.join(", ") + "{display: none !important;}",
-    cssOrigin: "user",
     frameId,
     matchAboutBlank: true,
     runAt: "document_start"
-  });
+  };
+
+  if (cssOriginSupported)
+    options.cssOrigin = "user";
+
+  browser.tabs.insertCSS(tabId, options);
 }
 
 port.on("elemhide.getSelectors", (msg, sender) =>
 {
   let selectors = [];
   let emulatedPatterns = [];
   let trace = devtools && devtools.hasPanel(sender.page);
   let inject = !userStyleSheetsSupported;