Cancel drag if display configuration changes.

ui/views/widget/x11_desktop_window_move_client.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/x11_desktop_window_move_client.h"
 
 #include <X11/Xlib.h>
 // Get rid of a macro from Xlib.h that conflicts with Aura's RootWindow class.
 #undef RootWindow
 
@@ skipping 51 matching lines @@
     ui::TouchEvent* event) {
   return ui::TOUCH_STATUS_UNKNOWN;
 }
 
 ui::EventResult X11DesktopWindowMoveClient::PreHandleGestureEvent(
     aura::Window* target,
     ui::GestureEvent* event) {
   return ui::ER_UNHANDLED;
 }
 
-void X11DesktopWindowMoveClient::RunMoveLoop(aura::Window* source,
-                                             const gfx::Point& drag_offset) {
+aura::client::WindowMoveResult X11DesktopWindowMoveClient::RunMoveLoop(
+    aura::Window* source,
+    const gfx::Point& drag_offset) {
   DCHECK(!in_move_loop_);  // Can only handle one nested loop at a time.
   in_move_loop_ = true;
   window_offset_ = drag_offset;
 
   source->GetRootWindow()->ShowRootWindow();
 
   Display* display = base::MessagePumpAuraX11::GetDefaultXDisplay();
   XGrabServer(display);
   XUngrabPointer(display, CurrentTime);
 
   aura::RootWindow* root_window = source->GetRootWindow();
   int ret = XGrabPointer(display,
                          root_window->GetAcceleratedWidget(),
                          False,
                          ButtonReleaseMask | PointerMotionMask,
                          GrabModeAsync,
                          GrabModeAsync,
                          None,
                          None,
                          CurrentTime);
   XUngrabServer(display);
   if (ret != GrabSuccess) {
     DLOG(ERROR) << "Grabbing new tab for dragging failed: " << ret;
-    return;
+    return aura::client::MOVE_CANCELED;
   }
 
   MessageLoopForUI* loop = MessageLoopForUI::current();
   MessageLoop::ScopedNestableTaskAllower allow_nested(loop);
   base::RunLoop run_loop(aura::Env::GetInstance()->GetDispatcher());
   quit_closure_ = run_loop.QuitClosure();
   run_loop.Run();
+  return aura::client::MOVE_SUCCESSFUL;
 }
 
 void X11DesktopWindowMoveClient::EndMoveLoop() {
   if (!in_move_loop_)
     return;
 
   // TODO(erg): Is this ungrab the cause of having to click to give input focus
   // on drawn out windows? Not ungrabbing here screws the X server until I kill
   // the chrome process.
 
   // Ungrab before we let go of the window.
   Display* display = base::MessagePumpAuraX11::GetDefaultXDisplay();
   XUngrabPointer(display, CurrentTime);
 
   in_move_loop_ = false;
   quit_closure_.Run();
 }
 
 }  // namespace views