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

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/shelf/shelf_view.h"
 #include "ash/shelf/wm_shelf.h"
 #include "ash/shell.h"
 #include "ash/wm_window.h"
 #include "base/command_line.h"
 #include "base/location.h"
@@ skipping 145 matching lines @@
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(WindowSizerContextMenuTest);
 };
 
 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);
+  release_point.Offset(50, -153);

[dschuyler, 2017/05/08 20:46:58]

Consider a comment about the constants 50 and -153. (e.g. // 50 is the distance
to ______; -153 moves _____ to _____.)
or expressing them as constexpr's with descriptive names (e.g. 
constexpr int kDistanceTo_____ = 50;
constexpr int k______Delta = -513;
).

   ui_controls::SendMouseMoveNotifyWhenDone(
       chrome_icon.x(), chrome_icon.y(),
       base::Bind(&WindowSizerContextMenuTest::Step1, release_point));
   base::RunLoop().Run();
 }
 
 }  // namespace
 
 IN_PROC_BROWSER_TEST_F(WindowSizerContextMenuTest,
                        MAYBE_OpenBrowserUsingContextMenuOnOtherDisplay) {
@@ skipping 21 matching lines @@
 
   CloseBrowser(browser_list->get(0));
   OpenBrowserUsingContextMenuOnRootWindow(root_windows[0]);
 
   // Next new browser must be created on 1st display.
   ASSERT_EQ(1u, browser_list->size());
   EXPECT_EQ(root_windows[0],
             browser_list->get(0)->window()->GetNativeWindow()->GetRootWindow());
   EXPECT_EQ(root_windows[0], ash::Shell::GetRootWindowForNewWindows());
 }