[vr] Add incognito coloring

chrome/browser/android/vr_shell/ui_elements/ui_element.h

Index: chrome/browser/android/vr_shell/ui_elements/ui_element.h
diff --git a/chrome/browser/android/vr_shell/ui_elements/ui_element.h b/chrome/browser/android/vr_shell/ui_elements/ui_element.h
index 71dd842c42cfc474fde07d7fcd7632eed3764411..4ee49ae99cb5e733f0c3e9dea725029bf7167e43 100644
--- a/chrome/browser/android/vr_shell/ui_elements/ui_element.h
+++ b/chrome/browser/android/vr_shell/ui_elements/ui_element.h
@@ -10,6 +10,7 @@
 #include <vector>
 
 #include "base/macros.h"
+#include "chrome/browser/android/vr_shell/color_scheme.h"
 #include "chrome/browser/android/vr_shell/ui_elements/ui_element_debug_id.h"
 #include "device/vr/vr_types.h"
 #include "third_party/skia/include/core/SkColor.h"
@@ -243,6 +244,12 @@ class UiElement : public WorldRectangle {
   // allow finer control of element visibility.
   virtual void SetEnabled(bool enabled);
 
+  void SetMode(ColorScheme::Mode mode);
+  ColorScheme::Mode mode() const { return mode_; }
+
+ protected:
+  virtual void OnSetMode();
+
  private:
   // Valid IDs are non-negative.
   int id_ = -1;
@@ -316,6 +323,8 @@ class UiElement : public WorldRectangle {
 
   Transform transform_;
 
+  ColorScheme::Mode mode_ = ColorScheme::kModeNormal;
+
   DISALLOW_COPY_AND_ASSIGN(UiElement);
 };