Adds a factory function to ViewsDelegate for DesktopWindowTreeHost

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 "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/trace_event/trace_event.h"
@@ skipping 13 matching lines @@
 #include "ui/compositor/layer.h"
 #include "ui/display/screen.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/geometry/point_conversions.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/size_conversions.h"
 #include "ui/views/corewm/tooltip.h"
 #include "ui/views/corewm/tooltip_controller.h"
 #include "ui/views/drag_utils.h"
 #include "ui/views/view_constants_aura.h"
+#include "ui/views/views_delegate.h"
 #include "ui/views/widget/desktop_aura/desktop_capture_client.h"
 #include "ui/views/widget/desktop_aura/desktop_event_client.h"
 #include "ui/views/widget/desktop_aura/desktop_focus_rules.h"
 #include "ui/views/widget/desktop_aura/desktop_native_cursor_manager.h"
 #include "ui/views/widget/desktop_aura/desktop_screen_position_client.h"
 #include "ui/views/widget/desktop_aura/desktop_window_tree_host.h"
 #include "ui/views/widget/drop_helper.h"
 #include "ui/views/widget/focus_manager_event_handler.h"
 #include "ui/views/widget/native_widget_aura.h"
 #include "ui/views/widget/root_view.h"
@@ skipping 364 matching lines @@
   // bounds and maximized windows in bad ways.
   if (params.type == Widget::InitParams::TYPE_WINDOW &&
       !params.remove_standard_frame) {
     content_window_->SetProperty(aura::client::kAnimationsDisabledKey, true);
   }
   content_window_->SetType(GetAuraWindowTypeForWidgetType(params.type));
   content_window_->Init(params.layer_type);
   wm::SetShadowElevation(content_window_, wm::ShadowElevation::NONE);
 
   if (!desktop_window_tree_host_) {
-    desktop_window_tree_host_ =
-        params.desktop_window_tree_host
-            ? params.desktop_window_tree_host
-            : DesktopWindowTreeHost::Create(native_widget_delegate_, this);
+    if (params.desktop_window_tree_host) {
+      desktop_window_tree_host_ = params.desktop_window_tree_host;
+    } else if (!ViewsDelegate::GetInstance()
+                    ->desktop_window_tree_host_factory()
+                    .is_null()) {
+      desktop_window_tree_host_ =
+          ViewsDelegate::GetInstance()
+              ->desktop_window_tree_host_factory()
+              .Run(params, native_widget_delegate_, this)
+              .release();
+    } else {
+      desktop_window_tree_host_ =
+          DesktopWindowTreeHost::Create(native_widget_delegate_, this);
+    }
     host_.reset(desktop_window_tree_host_->AsWindowTreeHost());
   }
   desktop_window_tree_host_->Init(content_window_, params);
 
   host_->window()->AddChild(content_window_);
   host_->window()->SetProperty(kDesktopNativeWidgetAuraKey, this);
 
   host_->window()->AddObserver(new RootWindowDestructionObserver(this));
 
   // The WindowsModalityController event filter should be at the head of the
@@ skipping 765 matching lines @@
   if (cursor_reference_count_ == 0) {
     // We are the last DesktopNativeWidgetAura instance, and we are responsible
     // for cleaning up |cursor_manager_|.
     delete cursor_manager_;
     native_cursor_manager_ = NULL;
     cursor_manager_ = NULL;
   }
 }
 
 }  // namespace views