Load dev tools extensions in webviews

lib/browser/chrome-extension.js

@@ -81,8 +81,8 @@ const removeBackgroundPages = function (manifest) {
 }
 
 // Dispatch tabs events.
-const hookWindowForTabEvents = function (win) {
-  const tabId = win.webContents.id
+const hookWindowForTabEvents = function (win, webContents) {
+  const tabId = webContents.id
   for (const page of objectValues(backgroundPages)) {
     page.webContents.sendToAll('CHROME_TABS_ONCREATED', tabId)
   }
@@ -301,6 +301,7 @@ app.once('ready', function () {
       return manifest.name
     }
   }
+
   BrowserWindow.removeDevToolsExtension = function (name) {
     const manifest = manifestNameMap[name]
     if (!manifest) return
@@ -315,9 +316,13 @@ app.once('ready', function () {
   const init = BrowserWindow.prototype._init
   BrowserWindow.prototype._init = function () {
     init.call(this)
-    hookWindowForTabEvents(this)
-    this.webContents.on('devtools-opened', () => {
-      loadDevToolsExtensions(this, objectValues(manifestMap))
+    this._loadDevToolsExtensions(this.webContents)
+  }
+
+  BrowserWindow.prototype._loadDevToolsExtensions = function (webContents) {
+    hookWindowForTabEvents(this, webContents)
+    webContents.on('devtools-opened', function () {
+      loadDevToolsExtensions(webContents, objectValues(manifestMap))
     })
   }
 })

lib/browser/guest-view-manager.js

@@ -1,5 +1,6 @@
 'use strict'
 
+const BrowserWindow = require('electron').BrowserWindow
 const ipcMain = require('electron').ipcMain
 const webContents = require('electron').webContents
 
@@ -150,6 +151,10 @@ const createGuest = function (embedder, params) {
     embedder.send.apply(embedder, ['ELECTRON_GUEST_VIEW_INTERNAL_SIZE_CHANGED-' + guest.viewInstanceId].concat(args))
   })
 
+  // Enable DevTools extensions in guest view
+  const window = BrowserWindow.fromWebContents(embedder)
+  if (window) window._loadDevToolsExtensions(guest)
+
   return id
 }