Move Mus into chrome's process when running with --mus.

services/ui/display/screen_manager_forwarding.cc

Index: services/ui/display/screen_manager_forwarding.cc
diff --git a/services/ui/display/screen_manager_forwarding.cc b/services/ui/display/screen_manager_forwarding.cc
index 8953a3042bb6049b3d7e9596b32522c68854d68e..d34ed0d6fcffae868cba5f3f43ad51508c527c38 100644
--- a/services/ui/display/screen_manager_forwarding.cc
+++ b/services/ui/display/screen_manager_forwarding.cc
@@ -37,9 +37,15 @@ const DisplayMode* GetCorrespondingMode(const DisplaySnapshot& snapshot,
 
 }  // namespace
 
-ScreenManagerForwarding::ScreenManagerForwarding()
+ScreenManagerForwarding::ScreenManagerForwarding(bool in_process)
     : screen_(base::MakeUnique<display::ScreenBase>()), binding_(this) {
-  Screen::SetScreenInstance(screen_.get());
+  // TODO: We should probably have Mus use Ash's screen and not create a screen
+  // here at all for the in-process case. We'd need to add GetAllDisplays() to
+  // display::Screen to achieve that.
+  // Currently WS still uses this Screen, accessing it via
+  // ScreenManager::GetInstance()->GetScreen() (rather than Screen::GetScreen())
+  if (!in_process)
+    Screen::SetScreenInstance(screen_.get());
 }
 
 ScreenManagerForwarding::~ScreenManagerForwarding() {