views: Support Desktop Aura creation on Ozone

chrome/browser/ui/views/frame/browser_desktop_root_window_host_ozone.cc

+// Copyright (c) 2013 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/frame/browser_desktop_root_window_host_ozone.h"
+
+////////////////////////////////////////////////////////////////////////////////
+// BrowserDesktopRootWindowHostOzone, public:
+
+BrowserDesktopRootWindowHostOzone::BrowserDesktopRootWindowHostOzone(
+    views::internal::NativeWidgetDelegate* native_widget_delegate,
+    views::DesktopNativeWidgetAura* desktop_native_widget_aura,
+    BrowserView* browser_view)
+    : DesktopRootWindowHostOzone(native_widget_delegate,
+                                 desktop_native_widget_aura) {
+}
+
+BrowserDesktopRootWindowHostOzone::~BrowserDesktopRootWindowHostOzone() {
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// BrowserDesktopRootWindowHostOzone,
+//     BrowserDesktopRootWindowHost implementation:
+
+views::DesktopRootWindowHost*
+    BrowserDesktopRootWindowHostOzone::AsDesktopRootWindowHost() {
+  return this;
+}
+
+int BrowserDesktopRootWindowHostOzone::GetMinimizeButtonOffset() const {
+  return 0;
+}
+
+bool BrowserDesktopRootWindowHostOzone::UsesNativeSystemMenu() const {
+  return false;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// BrowserDesktopRootWindowHost, public:
+
+// static
+BrowserDesktopRootWindowHost*
+    BrowserDesktopRootWindowHost::CreateBrowserDesktopRootWindowHost(
+        views::internal::NativeWidgetDelegate* native_widget_delegate,
+        views::DesktopNativeWidgetAura* desktop_native_widget_aura,
+        BrowserView* browser_view,
+        BrowserFrame* browser_frame) {
+  return new BrowserDesktopRootWindowHostOzone(native_widget_delegate,

[kalyank, 2013/11/23 12:11:52]

Why not use the existing DesktopFactory interface to able to create the Ozone
version of BrowserDesktopRootWindowHost?
I mean DesktopFactoryOzone, would have have an api like:
BrowserDesktopRootWindowHost* CreateBrowserDesktopRootWindowHost(
	views::internal::NativeWidgetDelegate* native_widget_delegate,
        views::DesktopNativeWidgetAura* desktop_native_widget_aura,
        BrowserView* browser_view,
        BrowserFrame* browser_frame);
and  BrowserDesktopRootWindowHost::CreateBrowserDesktopRootWindowHost would call
this. This would avoid desktop_root_window_host_ozone.cc.

If your concern was that ozone implementations might not implement
BrowserDesktopRootWindowHost properly(implementing all proper interfaces),
BrowserDesktopRootWindowHost clearly documents the expectations.I guess this
should give all needed hints for ozone implementations to make sure that it
implements both views::DesktopRootWindowHost and BrowserDesktopRootWindowHost.
Clearly document, the purpose of CreateRootWindowHost and
CreateBrowserDesktopRootWindowHost in DesktopFactoryOzone.

+                                               desktop_native_widget_aura,
+                                               browser_view);
+}