Prevent gap when gesture-dragging in stacked tab mode

chrome/browser/ui/views/tabs/stacked_tab_strip_layout.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 "chrome/browser/ui/views/tabs/stacked_tab_strip_layout.h"
 
 #include <stdio.h>
 
 #include "base/logging.h"
 #include "base/metrics/user_metrics.h"
@@ skipping 69 matching lines @@
 
   base::RecordAction(UserMetricsAction("StackedTab_DragActiveTab"));
   int initial_x = ideal_x(active_index());
   // If we're at a particular edge and start dragging, expose all the tabs after
   // the tab (or before when dragging to the left).
   if (delta > 0 && initial_x == GetMinX(active_index())) {
     LayoutByTabOffsetAfter(active_index());
     AdjustStackedTabs();
   } else if (delta < 0 && initial_x == GetMaxX(active_index())) {
     LayoutByTabOffsetBefore(active_index());
-    ResetToIdealState();
+    AdjustStackedTabs();
   }
   int x = delta > 0 ?
       std::min(initial_x + delta, GetMaxDragX(active_index())) :
       std::max(initial_x + delta, GetMinDragX(active_index()));
   if (x != initial_x) {
     SetIdealBoundsAt(active_index(), x);
     if (delta > 0) {
       PushTabsAfter(active_index(), (x - initial_x));
       LayoutForDragBefore(active_index());
     } else {
@@ skipping 464 matching lines @@
   return width_ - trailing_offset - size_.width();
 }
 
 int StackedTabStripLayout::GetMinXCompressed(int index) const {
   DCHECK_GT(index, active_index());
   return std::max(
       width_ - width_for_count(tab_count() - index),
       ideal_x(active_index()) +
           stacked_padding_for_count(index - active_index()));
 }