Only support left/right maximizing at 50% width when the --ash-enable-alternate-caption-button

ash/wm/gestures/two_finger_drag_handler.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/wm/gestures/two_finger_drag_handler.h"
 
 #include "ash/wm/window_resizer.h"
 #include "ash/wm/window_util.h"
 #include "ash/wm/workspace/snap_sizer.h"
 #include "ui/aura/client/window_types.h"
@@ skipping 124 matching lines @@
       // For a swipe, the window either maximizes, minimizes, or snaps. In this
       // case, cancel the drag, and do the appropriate action.
       Reset();
 
       if (event.details().swipe_up()) {
         if (wm::CanMaximizeWindow(target))
           wm::MaximizeWindow(target);
       } else if (event.details().swipe_down() &&
                  wm::CanMinimizeWindow(target)) {
         wm::MinimizeWindow(target);
-      } else if (wm::CanSnapWindow(target)) {
-        ui::ScopedLayerAnimationSettings scoped_setter(
-            target->layer()->GetAnimator());
-        scoped_setter.SetPreemptionStrategy(
-            ui::LayerAnimator::REPLACE_QUEUED_ANIMATIONS);
-        internal::SnapSizer::SnapWindow(target,
-            event.details().swipe_left() ? internal::SnapSizer::LEFT_EDGE :
-                                           internal::SnapSizer::RIGHT_EDGE);
+      } else {
+        using internal::SnapSizer;
+        SnapSizer::Edge edge = event.details().swipe_left() ?
+            SnapSizer::LEFT_EDGE : SnapSizer::RIGHT_EDGE;
+        if (SnapSizer::CanSnapWindow(target, edge)) {
+          ui::ScopedLayerAnimationSettings scoped_setter(
+              target->layer()->GetAnimator());
+          scoped_setter.SetPreemptionStrategy(
+              ui::LayerAnimator::REPLACE_QUEUED_ANIMATIONS);
+          SnapSizer::SnapWindow(target, edge, SnapSizer::STEP_NO);
+        }
       }
       return true;
     }
 
     case ui::ET_GESTURE_PINCH_UPDATE:
     case ui::ET_GESTURE_SCROLL_UPDATE:
       window_resizer_->Drag(event.details().bounding_box().CenterPoint(),
                             event.flags());
       return true;
 
@@ skipping 26 matching lines @@
                                                      bool visible) {
   Reset();
 }
 
 void TwoFingerDragHandler::OnWindowDestroying(aura::Window* window) {
   Reset();
 }
 
 }  // namespace internal
 }  // namespace ash