Hide docked windows behind a flag

ash/common/wm/workspace/workspace_window_resizer.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 "ash/common/wm/workspace/workspace_window_resizer.h"
 
 #include <algorithm>
 #include <cmath>
 #include <utility>
 #include <vector>
 
+#include "ash/common/ash_switches.h"
 #include "ash/common/metrics/user_metrics_action.h"
 #include "ash/common/wm/default_window_resizer.h"
 #include "ash/common/wm/dock/docked_window_layout_manager.h"
 #include "ash/common/wm/dock/docked_window_resizer.h"
 #include "ash/common/wm/panels/panel_window_resizer.h"
 #include "ash/common/wm/window_positioning_utils.h"
 #include "ash/common/wm/window_state.h"
 #include "ash/common/wm/wm_event.h"
 #include "ash/common/wm/wm_screen_util.h"
 #include "ash/common/wm/workspace/phantom_window_controller.h"
@@ skipping 856 matching lines @@
       SetDraggedWindowDocked(false);
       return;
     }
   }
 
   DCHECK(snap_type_ == SNAP_LEFT || snap_type_ == SNAP_RIGHT);
   DockedAlignment desired_alignment = (snap_type_ == SNAP_LEFT)
                                           ? DOCKED_ALIGNMENT_LEFT
                                           : DOCKED_ALIGNMENT_RIGHT;
   const bool can_dock =
+      ash::switches::DockedWindowsEnabled() &&
       dock_layout_->CanDockWindow(GetTarget(), desired_alignment) &&
       dock_layout_->GetAlignmentOfWindow(GetTarget()) != DOCKED_ALIGNMENT_NONE;
   if (!can_dock) {
     // If the window cannot be docked, undock the window. This may change the
     // workspace bounds and hence |snap_type_|.
     SetDraggedWindowDocked(false);
     snap_type_ = GetSnapType(location);
   }
   const bool can_snap = snap_type_ != SNAP_NONE && window_state()->CanSnap();
   if (!can_snap && !can_dock) {
@@ skipping 113 matching lines @@
   DCHECK(snapped_type == wm::WINDOW_STATE_TYPE_LEFT_SNAPPED ||
          snapped_type == wm::WINDOW_STATE_TYPE_RIGHT_SNAPPED);
   gfx::Rect snapped_bounds = wm::GetDisplayWorkAreaBoundsInParent(GetTarget());
   if (snapped_type == wm::WINDOW_STATE_TYPE_RIGHT_SNAPPED)
     snapped_bounds.set_x(snapped_bounds.right() - bounds_in_parent.width());
   snapped_bounds.set_width(bounds_in_parent.width());
   return bounds_in_parent == snapped_bounds;
 }
 
 }  // namespace ash