AdjustBoundsToEnsureMinimumWindowVisibility may cause unwanted shift if window dimension is small

ash/common/wm/default_state.cc

 // Copyright 2014 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/common/wm/default_state.h"
 
 #include "ash/common/shell_window_ids.h"
 #include "ash/common/wm/dock/docked_window_layout_manager.h"
 #include "ash/common/wm/window_animation_types.h"
 #include "ash/common/wm/window_parenting_utils.h"
@@ skipping 458 matching lines @@
       if (window_state->is_dragged() ||
           SetMaximizedOrFullscreenBounds(window_state)) {
         return true;
       }
       gfx::Rect work_area_in_parent =
           GetDisplayWorkAreaBoundsInParent(window_state->window());
       gfx::Rect bounds = window_state->window()->GetBounds();
       wm::AdjustBoundsToEnsureMinimumWindowVisibility(work_area_in_parent,
                                                       &bounds);
       window_state->AdjustSnappedBounds(&bounds);
-      if (window_state->window()->GetBounds() != bounds)
+      if (window_state->window()->GetBounds() != bounds &&
+          !window_state->ignored_by_shelf())

[sky, 2016/08/25 15:19:30]

ignored_by_shelf means:

  // True if the window is ignored by the shelf layout manager for
  // purposes of darkening the shelf.

You're changing the meaning to include don't adjust bounds on workspace area
changed. I don't think ignored_by_shelf should mean these two things.

I see two options:
1. ash shouldn't change the bounds of anything on a resize. This way client code
can do what it wants and we don't have race conditions. 
2. Add a property with the meaning of what you want, don't resize on workspace
change.
3. Only run this code on windows of type WINDOW_TYPE_NORMAL.

3 seems right to me, but there may be subtlety.

         window_state->SetBoundsDirectAnimated(bounds);
       return true;
     }
     case WM_EVENT_TOGGLE_MAXIMIZE_CAPTION:
     case WM_EVENT_TOGGLE_MAXIMIZE:
     case WM_EVENT_TOGGLE_VERTICAL_MAXIMIZE:
     case WM_EVENT_TOGGLE_HORIZONTAL_MAXIMIZE:
     case WM_EVENT_TOGGLE_FULLSCREEN:
     case WM_EVENT_CYCLE_SNAP_DOCK_LEFT:
     case WM_EVENT_CYCLE_SNAP_DOCK_RIGHT:
@@ skipping 263 matching lines @@
     gfx::Rect center_in_parent = GetDisplayWorkAreaBoundsInParent(window);
     center_in_parent.ClampToCenteredSize(window->GetBounds().size());
     window_state->SetBoundsDirectAnimated(center_in_parent);
   }
   // Centering window is treated as if a user moved and resized the window.
   window_state->set_bounds_changed_by_user(true);
 }
 
 }  // namespace wm
 }  // namespace ash