Fix opacity getting stuck when clicking on a new window while it's being created

ash/common/wm/drag_details.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/drag_details.h"
 
 #include "ash/common/wm/window_resizer.h"
 #include "ash/common/wm_window.h"
 #include "ash/common/wm_window_property.h"
 #include "ui/base/hit_test.h"
@@ skipping 32 matching lines @@
 
 }  // namespace
 
 DragDetails::DragDetails(WmWindow* window,
                          const gfx::Point& location,
                          int window_component,
                          aura::client::WindowMoveSource source)
     : initial_state_type(window->GetWindowState()->GetStateType()),
       initial_bounds_in_parent(window->GetBounds()),
       initial_location_in_parent(location),
-      initial_opacity(window->GetLayer()->opacity()),
+      // When drag starts, we might be in the middle of a window opacity
+      // animation, on drag completion we must set the opacity to the target
+      // opacity rather than the current opacity (crbug.com/687003).
+      initial_opacity(window->GetLayer()->GetTargetOpacity()),

[sky, 2017/02/06 22:37:59]

This is subtle. I would be nice to have test coverage.

       window_component(window_component),
       bounds_change(
           WindowResizer::GetBoundsChangeForWindowComponent(window_component)),
       position_change_direction(
           WindowResizer::GetPositionChangeDirectionForWindowComponent(
               window_component)),
       size_change_direction(
           GetSizeChangeDirectionForWindowComponent(window_component)),
       is_resizable(bounds_change != WindowResizer::kBoundsChangeDirection_None),
       source(source),
       should_attach_to_shelf(
           window->GetType() == ui::wm::WINDOW_TYPE_PANEL &&
           window->GetBoolProperty(WmWindowProperty::PANEL_ATTACHED)) {
   wm::WindowState* window_state = window->GetWindowState();
   if ((window_state->IsNormalOrSnapped() || window_state->IsDocked()) &&
       window_state->HasRestoreBounds() && window_component == HTCAPTION) {
     restore_bounds = window_state->GetRestoreBoundsInScreen();
   }
 }
 
 DragDetails::~DragDetails() {}
 
 }  // namespace ash