Bug 1575490 - move inspector browser toolbox pref from the server to the client; r=jdescottes

Differential Revision: https://phabricator.services.mozilla.com/D42817

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

devtools/server/actors/inspector/node.js

@@ -145,11 +145,6 @@ const SUBGRID_ENABLED = Services.prefs.getBoolPref(
   "layout.css.grid-template-subgrid-value.enabled"
 );
 
-const BROWSER_TOOLBOX_FISSION_ENABLED = Services.prefs.getBoolPref(
-  "devtools.browsertoolbox.fission",
-  false
-);
-
 const FONT_FAMILY_PREVIEW_TEXT = "The quick brown fox jumps over the lazy dog";
 const FONT_FAMILY_PREVIEW_TEXT_SIZE = 20;
 
@@ -317,8 +312,7 @@ const NodeActor = protocol.ActorClassWithSpec(nodeSpec, {
     return (
       this.numChildren == 0 &&
       ChromeUtils.getClassName(this.rawNode) == "XULFrameElement" &&
-      this.rawNode.getAttribute("remote") == "true" &&
-      BROWSER_TOOLBOX_FISSION_ENABLED
+      this.rawNode.getAttribute("remote") == "true"
     );
   },
 

devtools/shared/fronts/node.js

@@ -12,6 +12,7 @@ const {
 } = require("devtools/shared/protocol.js");
 const { nodeSpec, nodeListSpec } = require("devtools/shared/specs/node");
 const { SimpleStringFront } = require("devtools/shared/fronts/string");
+const Services = require("Services");
 
 loader.lazyRequireGetter(
   this,
@@ -26,6 +27,11 @@ loader.lazyRequireGetter(
   true
 );
 
+const BROWSER_TOOLBOX_FISSION_ENABLED = Services.prefs.getBoolPref(
+  "devtools.browsertoolbox.fission",
+  false
+);
+
 const HIDDEN_CLASS = "__fx-devtools-hide-shortcut__";
 
 /**
@@ -280,7 +286,7 @@ class NodeFront extends FrontClassWithSpec(nodeSpec) {
     return this._form.numChildren;
   }
   get remoteFrame() {
-    return this._form.remoteFrame;
+    return BROWSER_TOOLBOX_FISSION_ENABLED && this._form.remoteFrame;
   }
   get hasEventListeners() {
     return this._form.hasEventListeners;
@@ -512,6 +518,10 @@ class NodeFront extends FrontClassWithSpec(nodeSpec) {
   }
 
   async connectToRemoteFrame() {
+    if (!this.remoteFrame) {
+      console.warn("Tried to open remote connection to an invalid frame.");
+      return null;
+    }
     if (this._remoteFrameTarget) {
       return this._remoteFrameTarget;
     }