Treat NotifyVirtual events as mouse move events for blink.

ui/events/blink/web_input_event.cc

 // Copyright 2016 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/events/blink/web_input_event.h"
 
 #include "ui/events/base_event_utils.h"
 #include "ui/events/blink/blink_event_util.h"
 #include "ui/events/blink/blink_features.h"
 #include "ui/events/event.h"
 #include "ui/events/event_utils.h"
 #include "ui/events/keycodes/dom/keycode_converter.h"
 #include "ui/events/keycodes/keyboard_code_conversion.h"
 
 #if defined(OS_WIN)
 #include "ui/events/blink/web_input_event_builders_win.h"
 #endif
 
+#if defined(USE_X11)
+#include <X11/Xlib.h>
+#endif
+
 namespace ui {
 
 namespace {
 
 gfx::Point GetScreenLocationFromEvent(
     const LocatedEvent& event,
     const base::Callback<gfx::Point(const LocatedEvent& event)>&
         screen_location_callback) {
   DCHECK(!screen_location_callback.is_null());
   return event.target() ? screen_location_callback.Run(event)
@@ skipping 352 matching lines @@
   switch (event.type()) {
     case ET_MOUSE_PRESSED:
       type = blink::WebInputEvent::MouseDown;
       click_count = event.GetClickCount();
       break;
     case ET_MOUSE_RELEASED:
       type = blink::WebInputEvent::MouseUp;
       click_count = event.GetClickCount();
       break;
     case ET_MOUSE_EXITED: {
+#if defined(USE_X11)
+      // NotifyVirtual events are created for intermediate windows that the
+      // pointer crosses through. These occur when middle clicking.
+      // Change these into mouse move events.
+      const base::NativeEvent& native_event = event.native_event();
+
+      if (native_event && native_event->type == LeaveNotify &&
+          native_event->xcrossing.detail == NotifyVirtual) {
+        type = blink::WebInputEvent::MouseMove;
+        break;
+      }
+#endif
       static bool s_send_leave =
           base::FeatureList::IsEnabled(features::kSendMouseLeaveEvents);
       type = s_send_leave ? blink::WebInputEvent::MouseLeave
                           : blink::WebInputEvent::MouseMove;
       break;
     }
     case ET_MOUSE_ENTERED:
     case ET_MOUSE_MOVED:
     case ET_MOUSE_DRAGGED:
       type = blink::WebInputEvent::MouseMove;
@@ skipping 53 matching lines @@
   webkit_event.tiltX = roundf(event.pointer_details().tilt_x);
   webkit_event.tiltY = roundf(event.pointer_details().tilt_y);
   webkit_event.force = event.pointer_details().force;
   webkit_event.pointerType =
       EventPointerTypeToWebPointerType(event.pointer_details().pointer_type);
 
   return webkit_event;
 }
 
 }  // namespace ui