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..4a25247b4162fc25825a1530f3596a6d022b5ff4 100644
--- a/services/ui/display/screen_manager_forwarding.cc
+++ b/services/ui/display/screen_manager_forwarding.cc
@@ -37,15 +37,19 @@ const DisplayMode* GetCorrespondingMode(const DisplaySnapshot& snapshot,
 
 }  // namespace
 
-ScreenManagerForwarding::ScreenManagerForwarding()
-    : screen_(base::MakeUnique<display::ScreenBase>()), binding_(this) {
-  Screen::SetScreenInstance(screen_.get());
+ScreenManagerForwarding::ScreenManagerForwarding(bool in_process)
+    : in_process_(in_process),
+      screen_(base::MakeUnique<display::ScreenBase>()),
+      binding_(this) {
+  if (!in_process_)
+    Screen::SetScreenInstance(screen_.get());
 }
 
 ScreenManagerForwarding::~ScreenManagerForwarding() {
   if (native_display_delegate_)
     native_display_delegate_->RemoveObserver(this);
-  Screen::SetScreenInstance(nullptr);
+  if (!in_process_)
+    Screen::SetScreenInstance(nullptr);
 }
 
 void ScreenManagerForwarding::AddInterfaces(