Attempt at fixing tab dragging crash. I believe the crash is happening

chrome/browser/ui/views/tabs/base_tab_strip.cc

 // Copyright (c) 2011 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/base_tab_strip.h"
 
 #include "base/logging.h"
 #include "chrome/browser/tabs/tab_strip_selection_model.h"
 #include "chrome/browser/ui/view_ids.h"
 #include "chrome/browser/ui/views/tabs/tab_drag_controller.h"
@@ skipping 325 matching lines @@
         size_to_selected = GetSizeNeededForTabs(tabs);
         x = size_to_selected - tab->width() + x;
       }
     }
   }
   DCHECK(!tabs.empty());
   DCHECK(std::find(tabs.begin(), tabs.end(), tab) != tabs.end());
   TabStripSelectionModel selection_model;
   if (!original_selection.IsSelected(model_index))
     selection_model.Copy(original_selection);
+  // Delete the existing DragController before creating a new one. We do this as
+  // creating the DragController remembers the TabContents delegates and we need
+  // to make sure the existing DragController isn't still a delegate.
+  drag_controller_.reset();
   drag_controller_.reset(TabDragController::Create(
       this, tab, tabs, gfx::Point(x, y), tab->GetMirroredXInView(event.x()),
       selection_model));
 }
 
 void BaseTabStrip::ContinueDrag(const views::MouseEvent& event) {
   // We can get called even if |MaybeStartDrag| wasn't called in the event of
   // a TabStrip animation when the mouse button is down. In this case we should
   // _not_ continue the drag because it can lead to weird bugs.
   if (drag_controller_.get()) {
@@ skipping 226 matching lines @@
     // Animate the view back to its correct position.
     GenerateIdealBounds();
     AnimateToIdealBounds();
   }
   bounds_animator_.AnimateViewTo(tab, ideal_bounds(TabIndexOfTab(tab)));
   // Install a delegate to reset the dragging state when done. We have to leave
   // dragging true for the tab otherwise it'll draw beneath the new tab button.
   bounds_animator_.SetAnimationDelegate(
       tab, new ResetDraggingStateDelegate(tab), true);
 }