mus: Introduce high-contrast mode in mus.

services/ui/ws/test_utils.cc

Index: services/ui/ws/test_utils.cc
diff --git a/services/ui/ws/test_utils.cc b/services/ui/ws/test_utils.cc
index f870d0a7956a581a5860e5deb24d3664b996c713..40debd5e20d291bf66542e2f115a4bff5dedccbe 100644
--- a/services/ui/ws/test_utils.cc
+++ b/services/ui/ws/test_utils.cc
@@ -120,6 +120,10 @@ ServerWindow* TestFrameGeneratorDelegate::GetRootWindow() {
   return root_.get();
 }
 
+bool TestFrameGeneratorDelegate::IsInHighContrastMode() {
+  return false;
+}
+
 const ViewportMetrics& TestFrameGeneratorDelegate::GetViewportMetrics() {
   return metrics_;
 }