Mark the ET_MOUSE_MOVED created from a pointer grab as synthesized.

ui/aura/env_input_state_controller.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/aura/env_input_state_controller.h"
 
 #include "ui/aura/client/screen_position_client.h"
 #include "ui/aura/env.h"
 #include "ui/events/event.h"
 #include "ui/gfx/geometry/point.h"
 
 namespace aura {
 
 void EnvInputStateController::UpdateStateForMouseEvent(
     const Window* window,
     const ui::MouseEvent& event) {
   switch (event.type()) {
     case ui::ET_MOUSE_PRESSED:
       Env::GetInstance()->set_mouse_button_flags(event.button_flags());
       break;
     case ui::ET_MOUSE_RELEASED:
       Env::GetInstance()->set_mouse_button_flags(
           event.button_flags() & ~event.changed_button_flags());
       break;
     default:
       break;
   }
 
+  // If a synthesized event is created from a native event (e.g. EnterNotify
+  // XEvents), then we should take the location as we would for a
+  // non-synthesized event.
   if (event.type() != ui::ET_MOUSE_CAPTURE_CHANGED &&
-      !(event.flags() & ui::EF_IS_SYNTHESIZED)) {
+      (!(event.flags() & ui::EF_IS_SYNTHESIZED) || event.HasNativeEvent())) {
     SetLastMouseLocation(window, event.root_location());
   }
 }
 
 void EnvInputStateController::UpdateStateForTouchEvent(
     const ui::TouchEvent& event) {
   switch (event.type()) {
     case ui::ET_TOUCH_PRESSED:
       touch_ids_down_ |= (1 << event.pointer_details().id);
       Env::GetInstance()->set_touch_down(touch_ids_down_ != 0);
@@ skipping 32 matching lines @@
   if (client) {
     gfx::Point location_in_screen = location_in_root;
     client->ConvertPointToScreen(root_window, &location_in_screen);
     Env::GetInstance()->set_last_mouse_location(location_in_screen);
   } else {
     Env::GetInstance()->set_last_mouse_location(location_in_root);
   }
 }
 
 }  // namespace aura