[MD] simplify and unify some ink drop center calculations

chrome/browser/ui/views/toolbar/app_menu_button.cc

Index: chrome/browser/ui/views/toolbar/app_menu_button.cc
diff --git a/chrome/browser/ui/views/toolbar/app_menu_button.cc b/chrome/browser/ui/views/toolbar/app_menu_button.cc
index 12c0e38dfdc7ac277baa9d7eda618c0c97d26bf7..473d42315b8398727a4c081d7119eada8865fe31 100644
--- a/chrome/browser/ui/views/toolbar/app_menu_button.cc
+++ b/chrome/browser/ui/views/toolbar/app_menu_button.cc
@@ -188,17 +188,6 @@ void AppMenuButton::SetTrailingMargin(int margin) {
   InvalidateLayout();
 }
 
-gfx::Point AppMenuButton::GetInkDropCenter() const {
-  // ToolbarView extends the bounds of the app button to the right in maximized
-  // mode. So instead of using the center point of local bounds, we use the
-  // center point (adjusted for RTL layouts) of the preferred size, which
-  // doesn't change in maximized mode.
-  const int visible_width = GetPreferredSize().width();
-  return gfx::Point(
-      (GetMirroredXWithWidthInView(0, visible_width) + visible_width) / 2,

[varkha, 2016/03/03 06:11:22]

I looked at it some more and I understand what happened here. This had a last
minute typo with the extra parentheses. This line was supposed to be simply:
  GetMirroredXWithWidthInView(0, visible_width) + visible_width / 2,
The calculation in back_button didn't have this problem. The mistake is only 1
pixel at 1x so I have missed it. Using 3x shows it nicely.

But doing this is even simpler (this is what I suggested in label_button.cc):
  gfx::Point center = image()->bounds().CenterPoint();
  center.set_x(GetMirroredXInView(center.x()));
  return center;

I have built it and without GetMirrorXxxxx calls RTL layout will be wrong.

-      height() / 2);
-}
-
 const char* AppMenuButton::GetClassName() const {
   return "AppMenuButton";
 }