Handle modified displays in mustash.

services/ui/display/platform_screen_stub.h

Index: services/ui/display/platform_screen_stub.h
diff --git a/services/ui/display/platform_screen_stub.h b/services/ui/display/platform_screen_stub.h
index 4ce23038a3216381995e2535eb089d910b66416c..787f497c2af7bcd2b770ba080cc4eefcb0ceaf60 100644
--- a/services/ui/display/platform_screen_stub.h
+++ b/services/ui/display/platform_screen_stub.h
@@ -7,9 +7,9 @@
 
 #include <stdint.h>
 
-#include "base/callback.h"
 #include "base/memory/weak_ptr.h"
 #include "services/ui/display/platform_screen.h"
+#include "services/ui/display/viewport_metrics.h"
 
 namespace display {
 
@@ -30,6 +30,10 @@ class PlatformScreenStub : public PlatformScreen {
   void RequestCloseDisplay(int64_t display_id) override;
   int64_t GetPrimaryDisplayId() const override;
 
+  // Sample display information.
+  int64_t display_id_ = 1;
+  ViewportMetrics display_metrics_;
+
   PlatformScreenDelegate* delegate_ = nullptr;
 
   base::WeakPtrFactory<PlatformScreenStub> weak_ptr_factory_;