Add support for a virtual display on ChromeOS

chrome/browser/media/desktop_media_list_ash.cc

Index: chrome/browser/media/desktop_media_list_ash.cc
diff --git a/chrome/browser/media/desktop_media_list_ash.cc b/chrome/browser/media/desktop_media_list_ash.cc
index d24ec21b2b1c493942bb5472bfe57dacb2610b98..f25af0b47a500983572485888883f705d63a3f87 100644
--- a/chrome/browser/media/desktop_media_list_ash.cc
+++ b/chrome/browser/media/desktop_media_list_ash.cc
@@ -11,6 +11,7 @@
 #include "base/hash.h"
 #include "base/logging.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/sys_info.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "chrome/browser/media/desktop_media_list_observer.h"
 #include "chrome/grit/generated_resources.h"
@@ -18,6 +19,7 @@
 #include "media/base/video_util.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/compositor/dip_util.h"
+#include "ui/display/chromeos/display_configurator.h"
 #include "ui/gfx/image/image.h"
 #include "ui/snapshot/snapshot.h"
 
@@ -209,6 +211,24 @@ void DesktopMediaListAsh::EnumerateSources(
           sources, root_windows[i], ash::kShellWindowId_DockedContainer);
     }
   }
+#if defined(OS_CHROMEOS)
+  // DisplayConfigurator only works when running on ChromeOS.
+  if (base::SysInfo::IsRunningOnChromeOS()) {
+    ui::DisplayConfigurator* configurator =
+        ash::Shell::GetInstance()->display_configurator();
+    if (configurator->GetVirtualDisplayId() ==
+        gfx::Display::kInvalidDisplayID) {
+      SourceDescription virtual_screen_source(
+          content::DesktopMediaID(
+              content::DesktopMediaID::TYPE_AURA_VIRTUAL_SCREEN, 0),
+          l10n_util::GetStringUTF16(
+              IDS_DESTOP_MEDIA_PICKER_VIRTUAL_SCREEN_NAME));
+      sources->push_back(virtual_screen_source);
+      // TODO(robert.bradford): crbug.com/425060 There is no thumbnail for the
+      // virtual screen right now.
+    }
+  }
+#endif
 }
 
 void DesktopMediaListAsh::CaptureThumbnail(content::DesktopMediaID id,