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

chrome/browser/media/media_stream_devices_controller.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/media/media_stream_devices_controller.h"
 
 #include "base/values.h"
 #include "chrome/browser/content_settings/content_settings_provider.h"
 #include "chrome/browser/content_settings/host_content_settings_map.h"
+#include "chrome/browser/extensions/api/tab_capture/tab_capture_registry.h"
+#include "chrome/browser/extensions/api/tab_capture/tab_capture_registry_factory.h"
 #include "chrome/browser/prefs/scoped_user_pref_update.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/common/content_settings.h"
 #include "chrome/common/pref_names.h"
 #include "content/public/common/media_stream_request.h"
 
 using content::BrowserThread;
 
 namespace {
@@ skipping 35 matching lines @@
       has_audio_ |= !it->second.empty();
     } else if (content::IsVideoMediaType(it->first)) {
       has_video_ |= !it->second.empty();
     }
   }
 }
 
 MediaStreamDevicesController::~MediaStreamDevicesController() {}
 
 bool MediaStreamDevicesController::DismissInfoBarAndTakeActionOnSettings() {
+  // For tab media requests, we need to make sure the request came from the
+  // extension API, so we check the registry here.
+  content::MediaStreamDeviceMap::const_iterator tab_video =
+      request_.devices.find(content::MEDIA_TAB_VIDEO_CAPTURE);
+  content::MediaStreamDeviceMap::const_iterator tab_audio =
+      request_.devices.find(content::MEDIA_TAB_AUDIO_CAPTURE);
+  if (tab_video != request_.devices.end() ||
+      tab_audio != request_.devices.end()) {
+    extensions::TabCaptureRegistry* registry =
+        extensions::TabCaptureRegistryFactory::GetForProfile(profile_);
+
+    DCHECK(tab_audio->second.size() || tab_video->second.size());

[no longer working on chromium, 2012/10/18 08:36:17]

use !tab_audio->second.empty(), the same for other places.

[justinlin, 2012/10/18 09:33:29]

Done.

+    std::string audio_device_id;
+    std::string video_device_id;
+
+    if (tab_audio->second.size())
+      audio_device_id = tab_audio->second[0].device_id;
+    if (tab_video->second.size())
+      video_device_id = tab_video->second[0].device_id;
+
+    if (!registry->VerifyRequest(!video_device_id.empty() ?
+                                 video_device_id : audio_device_id))

[no longer working on chromium, 2012/10/18 08:36:17]

Does it mean that we will have either video_device_id or audio_device_id, and
never both?

[no longer working on chromium, 2012/10/18 08:36:17]

add a { because "if" takes two line.

[justinlin, 2012/10/18 09:33:29]

Done.

[justinlin, 2012/10/18 09:33:29]

No, this is a little bit related to http://crbug.com/155444. The issue is that
DeviceRequest only has one requested_device_id, so we key the registry (where
extensions keep track of the media stream requests for tabs) by a single
device_id. If video is request, then we use that one, if not we use the one from
audio, but they will both be the same anyway. I think there's checks before this
that prevent us from getting here without a tab video device right now, but if
later we allowed only capturing tab audio, then we might not have a tab video
device here.

+      Deny();
+    else
+      Accept(audio_device_id, video_device_id, false);
+
+    return true;
+  }
+
   // Deny the request if the security origin is empty, this happens with
   // file access without |--allow-file-access-from-files| flag.
   if (request_.security_origin.is_empty()) {
     Deny();
     return true;
   }
 
   // Deny the request and don't show the infobar if there is no devices.
   if (!has_audio_ && !has_video_) {
     // TODO(xians): We should detect this in a early state, and post a callback
@@ skipping 246 matching lines @@
     for (content::MediaStreamDevices::const_iterator device_it =
              it->second.begin();
          device_it != it->second.end(); ++device_it) {
       const content::MediaStreamDevice& candidate = *device_it;
       if (candidate.device_id == device_id)
         return &candidate;
     }
   }
   return NULL;
 }