Make it possible to launch chrome --mash with ozone_platform={wayland|x11}, chromeos=0

chrome/browser/ui/views/chrome_browser_main_extra_parts_views.cc

 // Copyright (c) 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/chrome_browser_main_extra_parts_views.h"
 
 #include "chrome/browser/ui/views/chrome_constrained_window_views_client.h"
 #include "chrome/browser/ui/views/chrome_views_delegate.h"
 #include "components/constrained_window/constrained_window_views.h"
 
@@ skipping 26 matching lines @@
     views_delegate_.reset(new ChromeViewsDelegate);
 
   SetConstrainedWindowViewsClient(CreateChromeConstrainedWindowViewsClient());
 
 #if defined(USE_AURA)
   wm_state_.reset(new wm::WMState);
 #endif
 }
 
 void ChromeBrowserMainExtraPartsViews::PreCreateThreads() {
-#if defined(USE_AURA) && !defined(OS_CHROMEOS)
+#if defined(USE_AURA) && !defined(OS_CHROMEOS) && !defined(USE_OZONE)

[Tom (Use chromium acct), 2016/10/17 23:40:52]

We're definitely going to need an ozone screen at some point, maybe stub one
out?

[tonikitoo, 2016/10/18 04:55:06]

we are using screen_mus.

Calling this as is simply hit an assert in 

FATAL:desktop_factory_ozone.cc(21)] Check failed: impl_. DesktopFactoryOzone
accessed before constructed
#0 0x7f15e92f291e base::debug::StackTrace::StackTrace()
#1 0x7f15e9314940 logging::LogMessage::~LogMessage()
#2 0x7f15e49a36f8 views::DesktopFactoryOzone::GetInstance()
#3 0x7f15e49a3736 views::CreateDesktopScreen()
#4 0x55e5736aa332 ChromeBrowserMainExtraPartsViews::PreCreateThreads()
(..)

I think DesktopFactoryOzone is obsolete.

   // The screen may have already been set in test initialization.
   if (!display::Screen::GetScreen())
     display::Screen::SetScreenInstance(views::CreateDesktopScreen());
 #endif
 }
 
 void ChromeBrowserMainExtraPartsViews::ServiceManagerConnectionStarted(
     content::ServiceManagerConnection* connection) {
   DCHECK(connection);
 #if defined(USE_AURA)
   if (shell::ShellIsRemote()) {
     // TODO(rockot): Remove the blocking wait for init.
     // http://crbug.com/594852.
     base::RunLoop wait_loop;
     connection->SetInitializeHandler(wait_loop.QuitClosure());
     wait_loop.Run();
 
     input_device_client_.reset(new ui::InputDeviceClient());
     ui::mojom::InputDeviceServerPtr server;
     connection->GetConnector()->ConnectToInterface("service:ui", &server);
     input_device_client_->Connect(std::move(server));
 
     window_manager_connection_ = views::WindowManagerConnection::Create(
         connection->GetConnector(), connection->GetIdentity(),
         content::BrowserThread::GetTaskRunnerForThread(
             content::BrowserThread::IO));
   }
 #endif  // defined(USE_AURA)
 }