Use XGrabPointer instead of XChangeActivatePointerGrab() to change the cursor during a pointer grab

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 934 matching lines @@
     return;
 
   // Grabbing the mouse is asynchronous. However, we synchronously start
   // forwarding all mouse events received by Chrome to the
   // aura::WindowEventDispatcher which has capture. This makes capture
   // synchronous for all intents and purposes if either:
   // - |g_current_capture|'s X window has capture.
   // OR
   // - The topmost window underneath the mouse is managed by Chrome.
   DesktopWindowTreeHostX11* old_capturer = g_current_capture;
+
+  // Update |g_current_capture| prior to calling OnHostLostWindowCapture() to
+  // avoid releasing pointer grab.
   g_current_capture = this;
   if (old_capturer)
     old_capturer->OnHostLostWindowCapture();
 
-  unsigned int event_mask = PointerMotionMask | ButtonReleaseMask |
-                            ButtonPressMask;
-  XGrabPointer(xdisplay_, xwindow_, True, event_mask, GrabModeAsync,
-               GrabModeAsync, None, None, CurrentTime);
+  ui::GrabPointer(xwindow_, true, None);
 }
 
 void DesktopWindowTreeHostX11::ReleaseCapture() {
   if (g_current_capture == this) {
     // Release mouse grab asynchronously. A window managed by Chrome is likely
     // the topmost window underneath the mouse so the capture release being
     // asynchronous is likely inconsequential.
     g_current_capture = NULL;
-    XUngrabPointer(xdisplay_, CurrentTime);
+    ui::UngrabPointer();
 
     OnHostLostWindowCapture();
   }
 }
 
 void DesktopWindowTreeHostX11::SetCursorNative(gfx::NativeCursor cursor) {
   XDefineCursor(xdisplay_, xwindow_, cursor.platform());
 }
 
 void DesktopWindowTreeHostX11::MoveCursorToNative(const gfx::Point& location) {
@@ skipping 946 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