Enable the mozilla/avoid-removeChild ESLint rule globally

This rule is available from https://www.npmjs.com/package/eslint-plugin-mozilla, and is enforced in mozilla-central. Note that we have a polyfill for `ChildNode.remove()` and that most cases have already been fixed, see PRs 8056 and 8138.

.eslintrc

@@ -4,6 +4,10 @@
     "sourceType": "module",
   },
 
+  "plugins": [
+    "mozilla"
+  ],
+
   "env": {
     "browser": true,
     "es6": true,
@@ -18,6 +22,9 @@
   },
 
   "rules": {
+    // Plugins
+    "mozilla/avoid-removeChild": "error",
+
     // Possible errors
     "for-direction": "error",
     "no-cond-assign": ["error", "except-parens"],

src/shared/compatibility.js

@@ -152,6 +152,7 @@ PDFJS.compatibilityChecked = true;
   }
   Element.prototype.remove = function () {
     if (this.parentNode) {
+      // eslint-disable-next-line mozilla/avoid-removeChild
       this.parentNode.removeChild(this);
     }
   };

test/driver.js

@@ -367,8 +367,7 @@ var Driver = (function DriverClosure() { // eslint-disable-line no-unused-vars
         while (styleSheet.cssRules.length > 0) {
           styleSheet.deleteRule(0);
         }
-        let ownerNode = styleSheet.ownerNode;
-        ownerNode.parentNode.removeChild(ownerNode);
+        styleSheet.ownerNode.remove();
       }
       let body = document.body;
       while (body.lastChild !== this.end) {

web/download_manager.js

@@ -43,7 +43,7 @@ function download(blobUrl, filename) {
     // (otherwise .click() is ignored)
     (document.body || document.documentElement).appendChild(a);
     a.click();
-    a.parentNode.removeChild(a);
+    a.remove();
   } else {
     if (window.top === window &&
         blobUrl.split('#')[0] === window.location.href.split('#')[0]) {

web/pdf_print_service.js

@@ -111,8 +111,8 @@ PDFPrintService.prototype = {
       return;
     }
     this.printContainer.textContent = '';
-    if (this.pageStyleSheet && this.pageStyleSheet.parentNode) {
-      this.pageStyleSheet.parentNode.removeChild(this.pageStyleSheet);
+    if (this.pageStyleSheet) {
+      this.pageStyleSheet.remove();
       this.pageStyleSheet = null;
     }
     this.scratchCanvas.width = this.scratchCanvas.height = 0;