Fix use-after-free when browser is closed during a drop-drop on desktop Linux

ui/views/widget/desktop_aura/desktop_drag_drop_client_aurax11.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 "ui/views/widget/desktop_aura/desktop_drag_drop_client_aurax11.h"
 
 #include <X11/Xatom.h>
 
 #include "base/event_types.h"
 #include "base/lazy_instance.h"
@@ skipping 413 matching lines @@
   g_live_client_map.Get()[xwindow] = this;
 
   // Mark that we are aware of drag and drop concepts.
   unsigned long xdnd_version = kMinXdndVersion;
   XChangeProperty(xdisplay_, xwindow_, atom_cache_.GetAtom("XdndAware"),
                   XA_ATOM, 32, PropModeReplace,
                   reinterpret_cast<unsigned char*>(&xdnd_version), 1);
 }
 
 DesktopDragDropClientAuraX11::~DesktopDragDropClientAuraX11() {
+  // This is necessary when the parent native widget gets destroyed while a drag
+  // operation is in progress.
+  move_loop_->EndMoveLoop();
+  NotifyDragLeave();
+
   g_live_client_map.Get().erase(xwindow_);
-  // Make sure that all observers are unregistered from source and target
-  // windows. This may be necessary when the parent native widget gets destroyed
-  // while a drag operation is in progress.
-  NotifyDragLeave();
 }
 
 // static
 DesktopDragDropClientAuraX11* DesktopDragDropClientAuraX11::GetForWindow(
     ::Window window) {
   std::map< ::Window, DesktopDragDropClientAuraX11*>::const_iterator it =
       g_live_client_map.Get().find(window);
   if (it == g_live_client_map.Get().end())
     return NULL;
   return it->second;
@@ skipping 742 matching lines @@
     for (int x = 0; x < in_bitmap->width(); ++x) {
       if (SkColorGetA(in_row[x]) > kMinAlpha)
         return true;
     }
   }
 
   return false;
 }
 
 }  // namespace views