Bug 1786104 - Enable all ESLint rules on dom production files. r=smaug

This changes the block of disabled rules for dom to only reference test directories,
and then fixes the few failures in the two production files (rules: mozilla/use-services,
no-else-return, consistent-return).

Differential Revision: https://phabricator.services.mozilla.com/D155130

.eslintrc.js

@@ -278,29 +278,29 @@ module.exports = {
     },
     {
       files: [
-        "dom/animation/**",
+        "dom/animation/test/**",
         "dom/base/test/*.*",
         "dom/base/test/unit/test_serializers_entities*.js",
         "dom/base/test/unit_ipc/**",
         "dom/base/test/jsmodules/**",
-        "dom/base/*.*",
-        "dom/canvas/**",
-        "dom/encoding/**",
-        "dom/events/**",
-        "dom/fetch/**",
-        "dom/file/**",
-        "dom/html/**",
-        "dom/jsurl/**",
+        "dom/canvas/test/**",
+        "dom/encoding/test/**",
+        "dom/events/test/**",
+        "dom/fetch/tests/**",
+        "dom/file/ipc/tests/**",
+        "dom/file/tests/**",
+        "dom/html/test/**",
+        "dom/jsurl/test/**",
         "dom/media/tests/**",
-        "dom/media/webaudio/**",
+        "dom/media/webaudio/test/**",
         "dom/media/webrtc/tests/**",
-        "dom/media/webspeech/**",
-        "dom/messagechannel/**",
-        "dom/midi/**",
-        "dom/network/**",
-        "dom/payments/**",
-        "dom/performance/**",
-        "dom/permission/**",
+        "dom/media/webspeech/recognition/test/**",
+        "dom/media/webspeech/synth/test/**",
+        "dom/messagechannel/tests/**",
+        "dom/midi/tests/**",
+        "dom/network/tests/**",
+        "dom/payments/test/**",
+        "dom/performance/tests/**",
         "dom/quota/test/browser/**",
         "dom/quota/test/common/**",
         "dom/quota/test/mochitest/**",
@@ -308,19 +308,19 @@ module.exports = {
         "dom/security/test/cors/**",
         "dom/security/test/csp/**",
         "dom/security/test/mixedcontentblocker/**",
-        "dom/serviceworkers/**",
-        "dom/smil/**",
+        "dom/serviceworkers/test/**",
+        "dom/smil/test/**",
         "dom/tests/mochitest/**",
-        "dom/u2f/**",
-        "dom/vr/**",
-        "dom/webauthn/**",
-        "dom/webgpu/**",
-        "dom/websocket/**",
-        "dom/workers/**",
-        "dom/worklet/**",
-        "dom/xml/**",
-        "dom/xslt/**",
-        "dom/xul/**",
+        "dom/u2f/tests/**",
+        "dom/vr/test/**",
+        "dom/webauthn/tests/**",
+        "dom/webgpu/mochitest/**",
+        "dom/websocket/tests/**",
+        "dom/workers/test/**",
+        "dom/worklet/tests/**",
+        "dom/xml/test/**",
+        "dom/xslt/tests/**",
+        "dom/xul/test/**",
         "dom/ipc/test.xhtml",
       ],
       rules: {

dom/base/ContentAreaDropListener.jsm

@@ -142,9 +142,7 @@ ContentAreaDropListener.prototype = {
     }
     let uri = info.fixedURI;
 
-    let secMan = Cc["@mozilla.org/scriptsecuritymanager;1"].getService(
-      Ci.nsIScriptSecurityManager
-    );
+    let secMan = Services.scriptSecurityManager;
     let flags = secMan.STANDARD;
     if (disallowInherit) {
       flags |= secMan.DISALLOW_INHERIT_PRINCIPAL;
@@ -190,22 +188,13 @@ ContentAreaDropListener.prototype = {
       // TODO: Investigate and describe the difference between them,
       //       or use only one principal. (Bug 1367038)
       if (fallbackToSystemPrincipal) {
-        let secMan = Cc["@mozilla.org/scriptsecuritymanager;1"].getService(
-          Ci.nsIScriptSecurityManager
-        );
-        return secMan.getSystemPrincipal();
-      } else {
-        principalURISpec = "file:///";
+        return Services.scriptSecurityManager.getSystemPrincipal();
       }
+
+      principalURISpec = "file:///";
     }
-    let ioService = Cc["@mozilla.org/network/io-service;1"].getService(
-      Ci.nsIIOService
-    );
-    let secMan = Cc["@mozilla.org/scriptsecuritymanager;1"].getService(
-      Ci.nsIScriptSecurityManager
-    );
-    return secMan.createContentPrincipal(
-      ioService.newURI(principalURISpec),
+    return Services.scriptSecurityManager.createContentPrincipal(
+      Services.io.newURI(principalURISpec),
       {}
     );
   },

dom/base/DOMRequestHelper.jsm

@@ -79,9 +79,8 @@ DOMRequestIpcHelper.prototype = {
         if (!!aMsg.weakRef == this._listeners[name].weakRef) {
           this._listeners[name].count++;
           return;
-        } else {
-          throw Components.Exception("", Cr.NS_ERROR_FAILURE);
         }
+        throw Components.Exception("", Cr.NS_ERROR_FAILURE);
       }
 
       aMsg.weakRef
@@ -228,6 +227,7 @@ DOMRequestIpcHelper.prototype = {
     if (this._requests && this._requests[aId]) {
       return this._requests[aId];
     }
+    return undefined;
   },
 
   getPromiseResolver(aId) {
@@ -264,10 +264,7 @@ DOMRequestIpcHelper.prototype = {
   },
 
   _getRandomId() {
-    return Cc["@mozilla.org/uuid-generator;1"]
-      .getService(Ci.nsIUUIDGenerator)
-      .generateUUID()
-      .toString();
+    return Services.uuid.generateUUID().toString();
   },
 
   createRequest() {