linux_aura: Fix crash on drags from the omnibox.

ui/views/view.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.
 
 #define _USE_MATH_DEFINES // For VC++ to get M_PI. This has to be first.
 
 #include "ui/views/view.h"
 
 #include <algorithm>
 #include <cmath>
@@ skipping 167 matching lines @@
       paint_to_layer_(false),
       accelerator_registration_delayed_(false),
       accelerator_focus_manager_(NULL),
       registered_accelerator_count_(0),
       next_focusable_view_(NULL),
       previous_focusable_view_(NULL),
       focusable_(false),
       accessibility_focusable_(false),
       context_menu_controller_(NULL),
       drag_controller_(NULL),
+      currently_dragging_(false),
       post_dispatch_handler_(new internal::PostEventDispatchHandler(this)),
       native_view_accessibility_(NULL) {
   AddPostTargetHandler(post_dispatch_handler_.get());
 }
 
 View::~View() {
   if (parent_)
     parent_->RemoveChildView(this);
 
   for (Views::const_iterator i(children_.begin()); i != children_.end(); ++i) {
@@ skipping 2113 matching lines @@
   if (widget && widget->native_widget_private()->GetTooltipManager())
     widget->native_widget_private()->GetTooltipManager()->UpdateTooltip();
 }
 
 // Drag and drop ---------------------------------------------------------------
 
 bool View::DoDrag(const ui::LocatedEvent& event,
                   const gfx::Point& press_pt,
                   ui::DragDropTypes::DragEventSource source) {
 #if !defined(OS_MACOSX)
+  if (currently_dragging_)
+    return false;
+
   int drag_operations = GetDragOperations(press_pt);
   if (drag_operations == ui::DragDropTypes::DRAG_NONE)
     return false;
 
+  currently_dragging_ = true;

[Elliot Glaysher, 2013/08/14 21:15:55]

I vaguely remember us having some sort of scoped bool setter, but I can't seem
to find it. If you know what the class name is, I'd be happy to use it.

[sadrul, 2013/08/14 21:33:52]

I think you mean base::AutoReset.

+
   OSExchangeData data;
   WriteDragData(press_pt, &data);
 
   // Message the RootView to do the drag and drop. That way if we're removed
   // the RootView can detect it and avoid calling us back.
   gfx::Point widget_location(event.location());
   ConvertPointToWidget(this, &widget_location);
   GetWidget()->RunShellDrag(this, data, widget_location, drag_operations,
       source);
+
+  currently_dragging_ = false;
+
   return true;
 #else
   return false;
 #endif  // !defined(OS_MACOSX)
 }
 
 }  // namespace views