linux_aura: Close window when the OS requests it.

ui/views/widget/desktop_aura/desktop_native_widget_aura.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 "ui/views/widget/desktop_aura/desktop_native_widget_aura.h"
 
 #include "base/bind.h"
 #include "ui/aura/client/activation_client.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/client/stacking_client.h"
@@ skipping 217 matching lines @@
 #if defined(OS_LINUX)  // TODO(scottmg): http://crbug.com/180071
   window_->Show();
 #endif
 
   desktop_root_window_host_ = params.desktop_root_window_host ?
       params.desktop_root_window_host :
       DesktopRootWindowHost::Create(native_widget_delegate_,
                                     this, params.bounds);
   root_window_.reset(
       desktop_root_window_host_->Init(window_, params));
+  root_window_->AddRootWindowObserver(this);

[sky, 2013/05/29 00:05:31]

I like things that are balanced. Can you remove the observer too?

[Elliot Glaysher, 2013/05/29 00:11:05]

Done.

+
   stacking_client_.reset(
       new DesktopNativeWidgetAuraStackingClient(root_window_.get()));
   drop_helper_.reset(new DropHelper(
       static_cast<internal::RootView*>(GetWidget()->GetRootView())));
   aura::client::SetDragDropDelegate(window_, this);
 
   tooltip_manager_.reset(new views::TooltipManagerAura(window_, GetWidget()));
   tooltip_controller_.reset(
       new corewm::TooltipController(gfx::SCREEN_TYPE_NATIVE));
   aura::client::SetTooltipClient(root_window_.get(),
@@ skipping 587 matching lines @@
   DCHECK(drop_helper_.get() != NULL);
   drop_helper_->OnDragExit();
 }
 
 int DesktopNativeWidgetAura::OnPerformDrop(const ui::DropTargetEvent& event) {
   DCHECK(drop_helper_.get() != NULL);
   return drop_helper_->OnDrop(event.data(), event.location(),
       last_drop_operation_);
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// DesktopNativeWidgetAura, aura::RootWindowObserver implementation:
+
+void DesktopNativeWidgetAura::OnRootWindowHostCloseRequested(
+    const aura::RootWindow* root) {
+  Close();
+}
+
 }  // namespace views