Public Sessions - prompt the user for audioCapture/videoCapture requests

chrome/browser/media/webrtc/media_capture_devices_dispatcher.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/webrtc/media_capture_devices_dispatcher.h"
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/metrics/field_trial.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 22 matching lines @@
 #include "extensions/common/constants.h"
 #include "extensions/features/features.h"
 #include "media/base/media_switches.h"
 
 #if defined(OS_CHROMEOS)
 #include "ash/shell.h"
 #endif  // defined(OS_CHROMEOS)
 
 #if BUILDFLAG(ENABLE_EXTENSIONS)
 #include "chrome/browser/media/extension_media_access_handler.h"
+#include "chrome/browser/media/public_session_media_access_handler.h"
 #include "chrome/browser/media/webrtc/desktop_capture_access_handler.h"
 #include "chrome/browser/media/webrtc/tab_capture_access_handler.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/permissions/permissions_data.h"
 #endif
 
 using content::BrowserThread;
 using content::MediaCaptureDevices;
 using content::MediaStreamDevices;
@@ skipping 24 matching lines @@
 MediaCaptureDevicesDispatcher* MediaCaptureDevicesDispatcher::GetInstance() {
   return base::Singleton<MediaCaptureDevicesDispatcher>::get();
 }
 
 MediaCaptureDevicesDispatcher::MediaCaptureDevicesDispatcher()
     : is_device_enumeration_disabled_(false),
       media_stream_capture_indicator_(new MediaStreamCaptureIndicator()) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
 #if BUILDFLAG(ENABLE_EXTENSIONS)
-  media_access_handlers_.push_back(new ExtensionMediaAccessHandler());
+  auto extension_media_access_handler = new ExtensionMediaAccessHandler();
+  media_access_handlers_.push_back(
+      new PublicSessionMediaAccessHandler(*extension_media_access_handler));

[Devlin, 2016/11/30 19:02:48]

Hmm... this is a little weird.  I wonder if it would make more sense to have
PublicSessionMediaAccessHandler subclass ExtensionMediaAccessHandler, and then
media_access_handlers_.push_back(
    IsPublicSession() ?
        new PublicSessionExtensionMediaAccessHandler() :
        new ExtensionMediaAccessHandler());

That way, we always use the right handler (rather than relying on the first in
having first say).

[Sergey Ulanov, 2016/12/01 01:21:28]

I think this is a good suggestions. Also add ifdef for OS_CHROMEOS here and
compile the new access handler only on ChromeOS

[Ivan Šandrk, 2016/12/01 17:32:05]

Now I understand what Sergey originally meant with his comment to add a separate
class that acts as a wrapper around the original; I'm new to some concepts :)
Done to all, except I didn't use IsPublicSession() here because at this point
the user hasn't logged in yet.

+  media_access_handlers_.push_back(extension_media_access_handler);
   media_access_handlers_.push_back(new DesktopCaptureAccessHandler());
   media_access_handlers_.push_back(new TabCaptureAccessHandler());
 #endif
   media_access_handlers_.push_back(new PermissionBubbleMediaAccessHandler());
 }
 
 MediaCaptureDevicesDispatcher::~MediaCaptureDevicesDispatcher() {}
 
 void MediaCaptureDevicesDispatcher::RegisterProfilePrefs(
     user_prefs::PrefRegistrySyncable* registry) {
@@ skipping 336 matching lines @@
 #if BUILDFLAG(ENABLE_EXTENSIONS)
   for (MediaAccessHandler* handler : media_access_handlers_) {
     if (handler->SupportsStreamType(stream_type, nullptr)) {
       ToCaptureAccessHandlerBase(handler)->UpdateCapturingLinkSecured(
           render_process_id, render_frame_id, page_request_id, is_secure);
       break;
     }
   }
 #endif
 }