chromeos: Makes mushrome use simplified display management

ash/mus/test/ash_test_impl_mus.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 "ash/mus/test/ash_test_impl_mus.h"
 
 #include "ash/test/ash_test.h"
 #include "ash/wm_window.h"
+#include "base/command_line.h"
 #include "base/memory/ptr_util.h"
 #include "services/ui/public/cpp/property_type_converters.h"
 #include "services/ui/public/interfaces/window_manager.mojom.h"
 #include "ui/aura/window.h"
+#include "ui/display/display_switches.h"
 #include "ui/wm/core/window_util.h"
 
 namespace ash {
 namespace mus {
 namespace {
 
 // WmTestBase is abstract as TestBody() is pure virtual (the various TEST
 // macros have the implementation). In order to create WmTestBase we have to
 // subclass with an empty implementation of TestBody(). That's ok as the class
 // isn't used as a normal test here.
@@ skipping 10 matching lines @@
 };
 
 }  // namespace
 
 AshTestImplMus::AshTestImplMus()
     : wm_test_base_(base::MakeUnique<WmTestBaseImpl>()) {}
 
 AshTestImplMus::~AshTestImplMus() {}
 
 void AshTestImplMus::SetUp() {
+  // This matches what AshTestBase does.
+  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
+  if (!command_line->HasSwitch(::switches::kHostWindowBounds)) {

[kylechar, 2017/04/26 16:41:44]

Do tests need this to pass?

[sky, 2017/04/26 19:36:41]

Yes as otherwise the root ends up at a different size and some tests expect a
certain size.

+    command_line->AppendSwitchASCII(::switches::kHostWindowBounds,
+                                    "1+1-800x600");
+  }
+
   wm_test_base_->SetUp();
 }
 
 void AshTestImplMus::TearDown() {
   wm_test_base_->TearDown();
 }
 
 void AshTestImplMus::UpdateDisplay(const std::string& display_spec) {
   wm_test_base_->UpdateDisplay(display_spec);
 }
@@ skipping 39 matching lines @@
 }
 
 void AshTestImplMus::AddTransientChild(WmWindow* parent, WmWindow* window) {
   // TODO(sky): remove this as both classes can share same implementation now.
   ::wm::AddTransientChild(WmWindow::GetAuraWindow(parent),
                           WmWindow::GetAuraWindow(window));
 }
 
 }  // namespace mus
 }  // namespace ash