--- a/browser/base/content/test/static/browser_parsable_css.js
+++ b/browser/base/content/test/static/browser_parsable_css.js
@@ -64,17 +64,38 @@ let whitelist = [
   {sourceName: /webide\/skin\/logs\.css$/i,
    intermittent: true,
    errorMessage: /Property contained reference to invalid variable.*background/i,
    isFromDevTools: true},
   {sourceName: /devtools\/skin\/animationinspector\.css$/i,
    intermittent: true,
    errorMessage: /Property contained reference to invalid variable.*color/i,
    isFromDevTools: true},
+];
 
+if (!Services.prefs.getBoolPref("full-screen-api.unprefix.enabled")) {
+  whitelist.push({
+    sourceName: /(?:res|gre-resources)\/(ua|html)\.css$/i,
+    errorMessage: /Unknown pseudo-class .*\bfullscreen\b/i,
+    isFromDevTools: false
+  });
+}
+
+// Platform can be "linux", "macosx" or "win". If omitted, the exception applies to all platforms.
+let allowedImageReferences = [
+  // Bug 1302691
+  {file: "chrome://devtools/skin/images/dock-bottom-minimize@2x.png",
+   from: "chrome://devtools/skin/toolbox.css",
+   isFromDevTools: true},
+  {file: "chrome://devtools/skin/images/dock-bottom-maximize@2x.png",
+   from: "chrome://devtools/skin/toolbox.css",
+   isFromDevTools: true},
+];
+
+let propNameWhitelist = [
   // These are CSS custom properties that we found a definition of but
   // no reference to.
   // Bug 1441837
   {propName: "--in-content-category-text-active",
    isFromDevTools: false},
   // Bug 1441844
   {propName: "--chrome-nav-bar-separator-color",
    isFromDevTools: false},
@@ -126,35 +147,16 @@ let whitelist = [
   // These properties *are* actually referenced. Need to find why
   // their reference isn't getting counted.
   {propName: "--bezier-diagonal-color",
    isFromDevTools: true},
   {propName: "--bezier-grid-color",
    isFromDevTools: true},
 ];
 
-if (!Services.prefs.getBoolPref("full-screen-api.unprefix.enabled")) {
-  whitelist.push({
-    sourceName: /(?:res|gre-resources)\/(ua|html)\.css$/i,
-    errorMessage: /Unknown pseudo-class .*\bfullscreen\b/i,
-    isFromDevTools: false
-  });
-}
-
-// Platform can be "linux", "macosx" or "win". If omitted, the exception applies to all platforms.
-let allowedImageReferences = [
-  // Bug 1302691
-  {file: "chrome://devtools/skin/images/dock-bottom-minimize@2x.png",
-   from: "chrome://devtools/skin/toolbox.css",
-   isFromDevTools: true},
-  {file: "chrome://devtools/skin/images/dock-bottom-maximize@2x.png",
-   from: "chrome://devtools/skin/toolbox.css",
-   isFromDevTools: true},
-];
-
 // Add suffix to stylesheets' URI so that we always load them here and
 // have them parsed. Add a random number so that even if we run this
 // test multiple times, it would be unlikely to affect each other.
 const kPathSuffix = "?always-parse-css-" + Math.random();
 
 function dumpWhitelistItem(item) {
   return JSON.stringify(item, (key, value) => {
     return value instanceof RegExp ? value.toString() : value;
@@ -433,17 +435,17 @@ add_task(async function checkAllTheCSS()
       }
     }
   }
 
   // Check if all the properties that are defined are referenced.
   for (let [prop, refCount] of customPropsToReferencesMap) {
     if (!refCount) {
       let ignored = false;
-      for (let item of whitelist) {
+      for (let item of propNameWhitelist) {
         if (item.propName == prop &&
             isDevtools == item.isFromDevTools) {
           item.used = true;
           if (!item.platforms || item.platforms.includes(AppConstants.platform)) {
             ignored = true;
           }
           break;
         }
@@ -456,34 +458,28 @@ add_task(async function checkAllTheCSS()
 
   let messages = Services.console.getMessageArray();
   // Count errors (the test output will list actual issues for us, as well
   // as the ok(false) in messageIsCSSError.
   let errors = messages.filter(messageIsCSSError);
   is(errors.length, 0, "All the styles (" + allPromises.length + ") loaded without errors.");
 
   // Confirm that all whitelist rules have been used.
-  for (let item of whitelist) {
-    if (!item.used &&
-        (!item.platforms || item.platforms.includes(AppConstants.platform)) &&
-        isDevtools == item.isFromDevTools &&
-        !item.intermittent) {
-      ok(false, "Unused whitelist item. " + dumpWhitelistItem(item));
+  function checkWhitelist(list) {
+    for (let item of list) {
+      if (!item.used && isDevtools == item.isFromDevTools &&
+          (!item.platforms || item.platforms.includes(AppConstants.platform)) &&
+          !item.intermittent) {
+        ok(false, "Unused whitelist item: " + dumpWhitelistItem(item));
+      }
     }
   }
-
-  // Confirm that all file whitelist rules have been used.
-  for (let item of allowedImageReferences) {
-    if (!item.used && isDevtools == item.isFromDevTools &&
-        (!item.platforms || item.platforms.includes(AppConstants.platform))) {
-      ok(false, "Unused file whitelist item. " +
-                " file: " + item.file +
-                " from: " + item.from);
-    }
-  }
+  checkWhitelist(whitelist);
+  checkWhitelist(allowedImageReferences);
+  checkWhitelist(propNameWhitelist);
 
   // Clean up to avoid leaks:
   iframe.remove();
   doc.head.innerHTML = "";
   doc = null;
   iframe = null;
   win = null;
   hiddenFrame.destroy();