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

ui/views/controls/menu/menu_runner.cc

 // Copyright (c) 2012 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 "ui/views/controls/menu/menu_runner.h"
 
 #include <utility>
 
 #include "ui/views/controls/menu/menu_runner_handler.h"
 #include "ui/views/controls/menu/menu_runner_impl.h"
@@ skipping 35 matching lines @@
   }
 
   // The parent of the nested menu will have created a DisplayChangeListener, so
   // we avoid creating a DisplayChangeListener if nested. Drop menus are
   // transient, so we don't cancel in that case.
   if ((run_types_ & (IS_NESTED | FOR_DROP)) == 0 && parent) {
     display_change_listener_.reset(
         internal::DisplayChangeListener::Create(parent, this));
   }
 
-  if (run_types_ & CONTEXT_MENU) {
+  if ((run_types_ & CONTEXT_MENU) && !(run_types_ & FIXED_ANCHOR)) {
     switch (source_type) {
       case ui::MENU_SOURCE_NONE:
       case ui::MENU_SOURCE_KEYBOARD:
       case ui::MENU_SOURCE_MOUSE:
         anchor = MENU_ANCHOR_TOPLEFT;
         break;
       case ui::MENU_SOURCE_TOUCH:
       case ui::MENU_SOURCE_TOUCH_EDIT_MENU:
         anchor = MENU_ANCHOR_BOTTOMCENTER;
         break;
@@ skipping 16 matching lines @@
 base::TimeTicks MenuRunner::closing_event_time() const {
   return impl_->GetClosingEventTime();
 }
 
 void MenuRunner::SetRunnerHandler(
     std::unique_ptr<MenuRunnerHandler> runner_handler) {
   runner_handler_ = std::move(runner_handler);
 }
 
 }  // namespace views