Align the base of the shelf's context menu to the top edge of the shelf.

chrome/browser/ui/window_sizer/window_sizer_ash_uitest.cc

Index: chrome/browser/ui/window_sizer/window_sizer_ash_uitest.cc
diff --git a/chrome/browser/ui/window_sizer/window_sizer_ash_uitest.cc b/chrome/browser/ui/window_sizer/window_sizer_ash_uitest.cc
index 5ef9154d57ab71a8e4fc47060c49b7855ff2fb78..97533e075d89e04155f398cb5baed0b3d5ba19d4 100644
--- a/chrome/browser/ui/window_sizer/window_sizer_ash_uitest.cc
+++ b/chrome/browser/ui/window_sizer/window_sizer_ash_uitest.cc
@@ -163,7 +163,10 @@ void OpenBrowserUsingContextMenuOnRootWindow(aura::Window* root_window) {
   gfx::Point chrome_icon =
       GetChromeIconBoundsForRootWindow(root_window).CenterPoint();
   gfx::Point release_point = chrome_icon;
-  release_point.Offset(50, -120);
+  // 50 is the distance from the chrome icon to leftest of the screen.

[msw, 2017/05/10 22:18:23]

nit: s/leftest/the left edge/. Also, I'm not sure if this is accurate... why
would we need to offset the release point's x value by the distance between the
chrome icon and the left edge of the screen, if the x value is from
|chrome_icon|, which is already presumably the x-coordinate of the icon (the
distance between the icon and the left edge of the screen). Perhaps this
x-offset isn't needed?

[minch1, 2017/05/11 16:34:03]

This is only my own understanding, I didn't check this with the owner of this
line? I tried to make it as 0 locally, the UT passed locally. If Trybot results
are all agree here, does that means it is ok to make it as 0 here?

[msw, 2017/05/11 17:13:39]

Yeah, 0 sgtm; thanks for simplifying this mystifying value.

+  // -153 moves from the chrome icon to the "New window" in the opened context

[msw, 2017/05/10 22:18:23]

nit: // -153 moves the cursor up to the "New window" menu option.

+  // menu.
+  release_point.Offset(50, -153);
   ui_controls::SendMouseMoveNotifyWhenDone(
       chrome_icon.x(), chrome_icon.y(),
       base::Bind(&WindowSizerContextMenuTest::Step1, release_point));