Makes WindowTreeHost::InitHost() not Show the window

ui/views/mus/native_widget_mus.cc

 // Copyright 2015 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.
 
 // This has to be before any other includes, else default is picked up.
 // See base/logging for details on this.
 #define NOTIMPLEMENTED_POLICY 5
 
 #include "ui/views/mus/native_widget_mus.h"
 
@@ skipping 702 matching lines @@
   NativeWidgetAura::RegisterNativeWidgetForWindow(this, content_);
   aura::Window* hosted_window = window_tree_host_->window();
 
   ownership_ = params.ownership;
   window_->SetCanFocus(params.activatable ==
                        Widget::InitParams::ACTIVATABLE_YES);
   window_->SetCanAcceptEvents(params.accept_events);
 
   window_tree_host_->AddObserver(this);
   window_tree_host_->InitHost();
+  window_tree_host_->window()->Show();
   hosted_window->SetProperty(kMusWindow, window_);
 
   // TODO(moshayedi): crbug.com/641039. Investigate whether there are any cases
   // where we need input method but don't have the WindowManagerConnection here.
   if (WindowManagerConnection::Exists())
     input_method_->Init(WindowManagerConnection::Get()->connector());
 
   focus_client_ =
       base::MakeUnique<FocusControllerMus>(new FocusRulesImpl(hosted_window));
 
@@ skipping 831 matching lines @@
 
   gfx::Path mask_path;
   native_widget_delegate_->GetHitTestMask(&mask_path);
   // TODO(jamescook): Use the full path for the mask.
   gfx::Rect mask_rect =
       gfx::ToEnclosingRect(gfx::SkRectToRectF(mask_path.getBounds()));
   window_->SetHitTestMask(mask_rect);
 }
 
 }  // namespace views