Fix extension->id() nullptr access at TabCaptureAccessHandler::HandleRequest

chrome/browser/media/webrtc/tab_capture_access_handler.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/media/webrtc/tab_capture_access_handler.h"
 
 #include <utility>
 
 #include "chrome/browser/extensions/api/tab_capture/tab_capture_registry.h"
 #include "chrome/browser/media/webrtc/media_capture_devices_dispatcher.h"
@@ skipping 24 matching lines @@
 }
 
 void TabCaptureAccessHandler::HandleRequest(
     content::WebContents* web_contents,
     const content::MediaStreamRequest& request,
     const content::MediaResponseCallback& callback,
     const extensions::Extension* extension) {
   content::MediaStreamDevices devices;
   std::unique_ptr<content::MediaStreamUI> ui;
 
-  if (!extension)
+  if (!extension) {
     callback.Run(devices, content::MEDIA_DEVICE_TAB_CAPTURE_FAILURE,
                  std::move(ui));
+    return;
+  }
 
   Profile* profile =
       Profile::FromBrowserContext(web_contents->GetBrowserContext());
   extensions::TabCaptureRegistry* tab_capture_registry =
       extensions::TabCaptureRegistry::Get(profile);
   if (!tab_capture_registry) {
     NOTREACHED();
     callback.Run(devices, content::MEDIA_DEVICE_INVALID_STATE, std::move(ui));
     return;
   }
@@ skipping 19 matching lines @@
   if (!devices.empty()) {
     ui = MediaCaptureDevicesDispatcher::GetInstance()
              ->GetMediaStreamCaptureIndicator()
              ->RegisterMediaStream(web_contents, devices);
   }
   UpdateExtensionTrusted(request, extension);
   callback.Run(devices, devices.empty() ? content::MEDIA_DEVICE_INVALID_STATE
                                         : content::MEDIA_DEVICE_OK,
                std::move(ui));
 }