Fix flakiness in using touch with immersive fullscreen

chrome/browser/ui/views/frame/immersive_mode_controller_ash.cc

 // Copyright 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 "chrome/browser/ui/views/frame/immersive_mode_controller_ash.h"
 
 #include "ash/ash_switches.h"
 #include "ash/shell.h"
 #include "ash/wm/window_properties.h"
 #include "base/command_line.h"
@@ skipping 443 matching lines @@
     const content::NotificationDetails& details) {
   DCHECK_EQ(chrome::NOTIFICATION_FULLSCREEN_CHANGED, type);
   if (enabled_)
     UpdateUseMinimalChrome(LAYOUT_YES);
 }
 
 void ImmersiveModeControllerAsh::OnMouseEvent(ui::MouseEvent* event) {
   if (!enabled_)
     return;
 
+  // Counterintuitively, we can still get synthesized mouse moves when
+  // aura::client::CursorClient::IsMouseEventsEnabled() == false.
+  if (event->flags() & ui::EF_IS_SYNTHESIZED)
+    return;
+
   if (event->type() != ui::ET_MOUSE_MOVED &&
       event->type() != ui::ET_MOUSE_PRESSED &&
       event->type() != ui::ET_MOUSE_RELEASED &&
       event->type() != ui::ET_MOUSE_CAPTURE_CHANGED) {
     return;
   }
 
   // Mouse hover should not initiate revealing the top-of-window views while
   // |native_window_| is inactive.
   if (!views::Widget::GetWidgetForNativeWindow(native_window_)->IsActive())
@@ skipping 613 matching lines @@
   if (!native_window_)
     return;
   aura::RootWindow* root_window = native_window_->GetRootWindow();
   if (!root_window)
     return;
   if (observers_enabled_)
     root_window->AddPreTargetHandler(this);
   else
     root_window->RemovePreTargetHandler(this);
 }