Make the maximize button more easily hittable when there is a huge amount of tabs present

ash/wm/custom_frame_view_ash.cc

Index: ash/wm/custom_frame_view_ash.cc
diff --git a/ash/wm/custom_frame_view_ash.cc b/ash/wm/custom_frame_view_ash.cc
index 9852d16a799a1b38fa0dd84216ca07babb50aedb..da1dcd3c67081398a2fd79a84959f6458447fb45 100644
--- a/ash/wm/custom_frame_view_ash.cc
+++ b/ash/wm/custom_frame_view_ash.cc
@@ -90,7 +90,7 @@ gfx::Rect CustomFrameViewAsh::GetWindowBoundsForClientBounds(
                                                         client_bounds);
 }
 
-int CustomFrameViewAsh::NonClientHitTest(const gfx::Point& point) {
+int CustomFrameViewAsh::NonClientHitTest(const gfx::Point& point) const {
   return frame_painter_->NonClientHitTest(this, point);
 }