Support Audio for Desktop Capture

chrome/browser/media/desktop_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/desktop_capture_access_handler.h"
 
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "build/build_config.h"
+#include "chrome/browser/content_settings/host_content_settings_map_factory.h"
 #include "chrome/browser/media/desktop_streams_registry.h"
 #include "chrome/browser/media/media_capture_devices_dispatcher.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_finder.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/screen_capture_notification_ui.h"
 #include "chrome/browser/ui/simple_message_box.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/grit/generated_resources.h"
+#include "components/content_settings/core/browser/host_content_settings_map.h"
+#include "components/content_settings/core/common/content_settings.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/desktop_media_id.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/media_stream_request.h"
 #include "content/public/common/origin_util.h"
 #include "extensions/browser/app_window/app_window.h"
 #include "extensions/browser/app_window/app_window_registry.h"
 #include "extensions/common/constants.h"
@@ skipping 303 matching lines @@
     callback.Run(devices, content::MEDIA_DEVICE_INVALID_STATE, std::move(ui));
     return;
   }
 
   bool loopback_audio_supported = false;
 #if defined(USE_CRAS) || defined(OS_WIN)
   // Currently loopback audio capture is supported only on Windows and ChromeOS.
   loopback_audio_supported = true;
 #endif
 
+  bool loopback_audio_permitted = true;

[GeorgeZ, 2016/01/15 16:37:55]

Maybe use this flag for all audio share (such as tab audio)
change to 
bool audio_permitted = true;

[qiangchen, 2016/01/15 18:19:40]

Done.

+
+  const bool audio_support_flag_for_desktop_share =
+      base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEnableAudioSupportForDesktopShare);
+
+  if (audio_support_flag_for_desktop_share) {
+    Profile* profile =
+        Profile::FromBrowserContext(web_contents->GetBrowserContext());
+
+    GURL origin(web_contents->GetLastCommittedURL().GetOrigin());
+
+    ContentSetting result =
+        HostContentSettingsMapFactory::GetForProfile(profile)
+            ->GetContentSetting(
+                origin, origin,
+                ContentSettingsType::CONTENT_SETTINGS_TYPE_DESKTOP_AUDIO_SHARE,
+                std::string());
+
+    loopback_audio_permitted =
+        (result == ContentSetting::CONTENT_SETTING_ALLOW);
+  }
+
   // Audio is only supported for screen capture streams.
   bool capture_audio =
       (media_id.type == content::DesktopMediaID::TYPE_SCREEN &&
        request.audio_type == content::MEDIA_DESKTOP_AUDIO_CAPTURE &&
-       loopback_audio_supported);
+       loopback_audio_supported && loopback_audio_permitted);
 
   ui = GetDevicesForDesktopCapture(&devices, media_id, capture_audio, true,
                                    GetApplicationTitle(web_contents, extension),
                                    base::UTF8ToUTF16(original_extension_name));
 
   callback.Run(devices, content::MEDIA_DEVICE_OK, std::move(ui));
 }
 
 void DesktopCaptureAccessHandler::UpdateMediaRequestState(
     int render_process_id,
@@ skipping 22 matching lines @@
         desktop_capture_sessions_.erase(it);
         break;
       }
     }
   }
 }
 
 bool DesktopCaptureAccessHandler::IsCaptureInProgress() {
   return desktop_capture_sessions_.size() > 0;
 }