Rework tree APIs to reflect Google style and more const-correctness....

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

 // Copyright (c) 2011 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_frame_win.h"
 
 #include <dwmapi.h>
 #include <shellapi.h>
 
 #include <set>
@@ skipping 106 matching lines @@
   // Otherwise, we use the native frame when we're told we should by the theme
   // provider (e.g. no custom theme is active).
   return GetThemeProvider()->ShouldUseNativeFrame();
 }
 
 views::View* BrowserFrameWin::GetFrameView() const {
   return browser_frame_view_;
 }
 
 void BrowserFrameWin::TabStripDisplayModeChanged() {
-  if (GetRootView()->GetChildViewCount() > 0) {
+  if (GetRootView()->has_children()) {
     // Make sure the child of the root view gets Layout again.
     GetRootView()->GetChildViewAt(0)->InvalidateLayout();
   }
   GetRootView()->Layout();
 
   UpdateDWMFrame();
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 // BrowserFrame, views::WindowWin overrides:
@@ skipping 169 matching lines @@
       gfx::Rect tabstrip_bounds(
           GetBoundsForTabStrip(browser_view_->tabstrip()));
       margins.cyTopHeight = (browser_view_->UseVerticalTabs() ?
           tabstrip_bounds.y() : tabstrip_bounds.bottom()) + kDWMFrameTopOffset;
     }
   } else {
     // For popup and app windows we want to use the default margins.
   }
   DwmExtendFrameIntoClientArea(GetNativeView(), &margins);
 }