Rename KEY_ constants to avoid conflict with <linux/input.h>

ui/ozone/demo/ozone_demo.cc

Index: ui/ozone/demo/ozone_demo.cc
diff --git a/ui/ozone/demo/ozone_demo.cc b/ui/ozone/demo/ozone_demo.cc
index d92f0bb278a01ac06c76143856df50cd6383a7f6..1e386ebc1bd4dc85186e945c5ad7ac73e72924e0 100644
--- a/ui/ozone/demo/ozone_demo.cc
+++ b/ui/ozone/demo/ozone_demo.cc
@@ -146,7 +146,7 @@ class DemoWindow : public ui::PlatformWindowDelegate {
   void OnDamageRect(const gfx::Rect& damaged_region) override {}
   void DispatchEvent(ui::Event* event) override {
     if (event->IsKeyEvent() &&
-        static_cast<ui::KeyEvent*>(event)->code() == ui::DomCode::KEY_Q)
+        static_cast<ui::KeyEvent*>(event)->code() == ui::DomCode::US_Q)
       Quit();
   }
   void OnCloseRequest() override { Quit(); }