Bug 1625430 - Allow clean-up of the DOM event dispatching in the PDF …

…Viewer. r=bdahl

As part of the work to clean-up the event dispatching in the PDF Viewer, particularily re-dispatching of internal `EventBus` events to the DOM, this patch is necessary to unblock the upstream work that's currently pending in [PR 11655](mozilla/pdf.js#11655).

Finally, the patch also removes the `ChromeActions.supportsDocumentColors` method given that it's been unused since [bug 1611175](https://bugzilla.mozilla.org/show_bug.cgi?id=1611175) and [PR 11521](mozilla/pdf.js#11521).

Differential Revision: https://phabricator.services.mozilla.com/D68533

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

browser/extensions/pdfjs/content/PdfStreamConverter.jsm

@@ -385,17 +385,17 @@ class ChromeActions {
     return !!prefBrowser && prefGfx;
   }
 
-  supportsDocumentColors() {
-    return getIntPref("browser.display.document_color_use", 0) !== 2;
-  }
-
   supportedMouseWheelZoomModifierKeys() {
     return {
       ctrlKey: getIntPref("mousewheel.with_control.action", 3) === 3,
       metaKey: getIntPref("mousewheel.with_meta.action", 1) === 3,
     };
   }
 
+  isInAutomation() {
+    return Cu.isInAutomation;
+  }
+
   reportTelemetry(data) {
     var probeInfo = JSON.parse(data);
     switch (probeInfo.type) {