Fix grabbing capture when the mouse is pressed on Desktop Linux.

ui/events/devices/x11/touch_factory_x11.cc

Index: ui/events/devices/x11/touch_factory_x11.cc
diff --git a/ui/events/devices/x11/touch_factory_x11.cc b/ui/events/devices/x11/touch_factory_x11.cc
index 0a35527178403bd1fb484f729948562d46a78a2a..a62cb0c7a3d6e10c6969e0a4e0565c953e37dc62 100644
--- a/ui/events/devices/x11/touch_factory_x11.cc
+++ b/ui/events/devices/x11/touch_factory_x11.cc
@@ -205,6 +205,8 @@ void TouchFactory::SetupXI2ForXWindow(Window window) {
   XISetMask(mask, XI_ButtonRelease);
   XISetMask(mask, XI_Motion);
 #if defined(OS_CHROMEOS)
+  // XGrabKey() must be replaced with XI2 keyboard grab if XI2 key events are
+  // enabled on desktop Linux.
   if (base::SysInfo::IsRunningOnChromeOS()) {
     XISetMask(mask, XI_KeyPress);
     XISetMask(mask, XI_KeyRelease);