Support Audio for Desktop Capture

chrome/browser/media/desktop_capture_access_handler.cc

Index: chrome/browser/media/desktop_capture_access_handler.cc
diff --git a/chrome/browser/media/desktop_capture_access_handler.cc b/chrome/browser/media/desktop_capture_access_handler.cc
index 66f37c09d6c5595f9fe0f41566df0fb867f57727..285a4435e26bf591e3411bbcee65e422dc9a57cf 100644
--- a/chrome/browser/media/desktop_capture_access_handler.cc
+++ b/chrome/browser/media/desktop_capture_access_handler.cc
@@ -11,6 +11,7 @@
 #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"
@@ -20,6 +21,8 @@
 #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"
@@ -343,11 +346,34 @@ void DesktopCaptureAccessHandler::HandleRequest(
   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),