Pushed InkDropHost inheritence up to CustomButton.

ui/views/controls/button/custom_button.cc

Index: ui/views/controls/button/custom_button.cc
diff --git a/ui/views/controls/button/custom_button.cc b/ui/views/controls/button/custom_button.cc
index 76525064a7e34ab110e46752ecb27228656ec21a..859c7a1879e5669ac18d7b78b92d0994b63842cb 100644
--- a/ui/views/controls/button/custom_button.cc
+++ b/ui/views/controls/button/custom_button.cc
@@ -331,6 +331,13 @@ void CustomButton::AnimationProgressed(const gfx::Animation* animation) {
 }
 
 ////////////////////////////////////////////////////////////////////////////////
+// CustomButton, views::InkDropHost implementation:
+
+gfx::Point CustomButton::CalculateInkDropCenter() const {
+  return GetLocalBounds().CenterPoint();
+}
+
+////////////////////////////////////////////////////////////////////////////////
 // CustomButton, protected:
 
 CustomButton::CustomButton(ButtonListener* listener)