Remove persisted docked windows

chrome/browser/ui/views/apps/chrome_native_app_window_views_aura.cc

 // Copyright 2015 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 "chrome/browser/ui/views/apps/chrome_native_app_window_views_aura.h"
 
 #include <utility>
 
 #include "apps/ui/views/app_window_frame_view.h"
 #include "base/macros.h"
@@ skipping 85 matching lines @@
   // First normal states are checked.
   if (IsMaximized())
     return ui::SHOW_STATE_MAXIMIZED;
   if (IsFullscreen()) {
     return ui::SHOW_STATE_FULLSCREEN;
   }
 
   // Use kPreMinimizedShowStateKey in case a window is minimized/hidden.
   ui::WindowShowState restore_state = widget()->GetNativeWindow()->GetProperty(
       aura::client::kPreMinimizedShowStateKey);
+
+  // TODO(afakhry): Remove in M58.
   if (widget()->GetNativeWindow()->GetProperty(aura::client::kShowStateKey) ==
           ui::SHOW_STATE_DOCKED ||
       restore_state == ui::SHOW_STATE_DOCKED) {
     return ui::SHOW_STATE_DOCKED;
   }
 
   return GetRestorableState(restore_state);
 }
 
 bool ChromeNativeAppWindowViewsAura::IsAlwaysOnTop() const {
   return widget()->IsAlwaysOnTop();
 }
 
 void ChromeNativeAppWindowViewsAura::UpdateShape(
     std::unique_ptr<SkRegion> region) {
   bool had_shape = !!shape();
 
   ChromeNativeAppWindowViews::UpdateShape(std::move(region));
 
   aura::Window* native_window = widget()->GetNativeWindow();
   if (shape() && !had_shape) {
     native_window->SetEventTargeter(std::unique_ptr<ui::EventTargeter>(
         new ShapedAppWindowTargeter(native_window, this)));
   } else if (!shape() && had_shape) {
     native_window->SetEventTargeter(std::unique_ptr<ui::EventTargeter>());
   }
 }