[mus]Add FrameGenerator::SetHighContrastMode(bool)

services/ui/ws/frame_generator.h

Index: services/ui/ws/frame_generator.h
diff --git a/services/ui/ws/frame_generator.h b/services/ui/ws/frame_generator.h
index baf047913dc4f5dd9548605317820170054c7b86..49d0fb097631e866e561998d359a27a9ea877941 100644
--- a/services/ui/ws/frame_generator.h
+++ b/services/ui/ws/frame_generator.h
@@ -37,12 +37,12 @@ class FrameGenerator : public cc::CompositorFrameSinkClient,
                        public cc::BeginFrameObserver {
  public:
   FrameGenerator(
-      FrameGeneratorDelegate* delegate,
       ServerWindow* root_window,
       std::unique_ptr<cc::CompositorFrameSink> compositor_frame_sink);
   ~FrameGenerator() override;
 
   void SetDeviceScaleFactor(float device_scale_factor);
+  void SetHighContrastMode(bool enabled);
 
   // Updates the WindowManager's SurfaceInfo.
   void OnSurfaceCreated(const cc::SurfaceInfo& surface_info);
@@ -88,6 +88,7 @@ class FrameGenerator : public cc::CompositorFrameSinkClient,
   cc::BeginFrameArgs last_begin_frame_args_;
   cc::BeginFrameSource* begin_frame_source_ = nullptr;
   bool observing_begin_frames_ = false;
+  bool high_contrast_mode_enabled_ = false;
 
   cc::SurfaceInfo window_manager_surface_info_;