Color the ink drop ripple and hover effects based on theming.

ui/views/controls/button/custom_button.h

Index: ui/views/controls/button/custom_button.h
diff --git a/ui/views/controls/button/custom_button.h b/ui/views/controls/button/custom_button.h
index cae7dd089734dc1f42f10021728e0672be91d1d5..1ed491ea667d0b807b852a771ab9bdb1c5b80adb 100644
--- a/ui/views/controls/button/custom_button.h
+++ b/ui/views/controls/button/custom_button.h
@@ -75,6 +75,8 @@ class VIEWS_EXPORT CustomButton : public Button,
     notify_action_ = notify_action;
   }
 
+  void set_ink_drop_base_color(SkColor color) { ink_drop_base_color_ = color; }
+
   void SetHotTracked(bool is_hot_tracked);
   bool IsHotTracked() const;
 
@@ -108,6 +110,7 @@ class VIEWS_EXPORT CustomButton : public Button,
   void RemoveInkDropLayer(ui::Layer* ink_drop_layer) override;
   gfx::Point CalculateInkDropCenter() const override;
   bool ShouldShowInkDropHover() const override;
+  SkColor GetInkDropBaseColor() const override;
 
  protected:
   // Construct the Button with a Listener. See comment for Button's ctor.
@@ -199,6 +202,9 @@ class VIEWS_EXPORT CustomButton : public Button,
   // is clicked.
   InkDropState ink_drop_action_on_click_;
 
+  // The color of the ripple and hover.
+  SkColor ink_drop_base_color_;
+
   DISALLOW_COPY_AND_ASSIGN(CustomButton);
 };