Revert of Simplify the logic in DesktopWindowTreeHostX11 for FocusOut

ui/views/widget/desktop_aura/desktop_window_tree_host_x11.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_window_tree_host_x11.h"
 
 #include <X11/extensions/shape.h>
 #include <X11/extensions/XInput2.h>
 #include <X11/Xatom.h>
 #include <X11/Xregion.h>
@@ skipping 1577 matching lines @@
         }
         case ui::ET_UNKNOWN:
           // No event is created for X11-release events for mouse-wheel buttons.
           break;
         default:
           NOTREACHED() << event_type;
       }
       break;
     }
     case FocusOut:
-      ReleaseCapture();
-      X11DesktopHandler::get()->ProcessXEvent(xev);
+      if (xev->xfocus.mode != NotifyGrab) {
+        ReleaseCapture();
+        OnHostLostWindowCapture();
+        X11DesktopHandler::get()->ProcessXEvent(xev);
+      } else {
+        dispatcher()->OnHostLostMouseGrab();
+      }
       break;
     case FocusIn:
       X11DesktopHandler::get()->ProcessXEvent(xev);
       break;
     case ConfigureNotify: {
       DCHECK_EQ(xwindow_, xev->xconfigure.window);
       DCHECK_EQ(xwindow_, xev->xconfigure.event);
       // It's possible that the X window may be resized by some other means than
       // from within aura (e.g. the X window manager can change the size). Make
       // sure the root window size is maintained properly.
@@ skipping 205 matching lines @@
   if (linux_ui) {
     ui::NativeTheme* native_theme = linux_ui->GetNativeTheme(window);
     if (native_theme)
       return native_theme;
   }
 
   return ui::NativeTheme::instance();
 }
 
 }  // namespace views