Make tab capture media stream requests verify that the request came from extension API

chrome/browser/extensions/extension_host.cc

 // Copyright (c) 2012 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/extensions/extension_host.h"
 
 #include <list>
 
 #include "base/bind.h"
 #include "base/memory/singleton.h"
@@ skipping 622 matching lines @@
                               initial_pos, user_gesture);
 }
 
 void ExtensionHost::RenderViewReady() {
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_EXTENSION_HOST_CREATED,
       content::Source<Profile>(profile_),
       content::Details<ExtensionHost>(this));
 }
 
+void ExtensionHost::RequestMediaAccessPermission(
+    content::WebContents* web_contents,
+    const content::MediaStreamRequest* request,
+    const content::MediaResponseCallback& callback) {
+  content::MediaStreamDevices devices;
+
+  bool accepted_an_audio_device = false;
+  bool accepted_a_video_device = false;
+  for (content::MediaStreamDeviceMap::const_iterator it =
+       request->devices.begin(); it != request->devices.end(); ++it) {
+    if (!accepted_an_audio_device && content::IsAudioMediaType(it->first) &&
+        !it->second.empty()) {
+      // For tab capture, we require the tabCapture permission.
+      if (it->first != content::MEDIA_TAB_AUDIO_CAPTURE ||
+          extension()->HasAPIPermission(APIPermission::kTabCapture)) {
+        devices.push_back(it->second.front());
+        accepted_an_audio_device = true;
+      }
+    } else if (!accepted_a_video_device &&
+               content::IsVideoMediaType(it->first) && !it->second.empty()) {
+      if (it->first != content::MEDIA_TAB_VIDEO_CAPTURE ||
+          extension()->HasAPIPermission(APIPermission::kTabCapture)) {
+        devices.push_back(it->second.front());
+        accepted_a_video_device = true;
+      }
+    }
+  }
+
+  callback.Run(devices);
+}
+
 }  // namespace extensions