alternate ntp: fix website page jankiness when suggestions show and top bars are hidden

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

 // Copyright 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 "chrome/browser/ui/views/frame/contents_container.h"
 
 #include "grit/theme_resources.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/image/image_skia.h"
@@ skipping 157 matching lines @@
   // back.
   // See comments in SetPreview() for why shadow view is removed.
   bool removed_shadow = RemoveShadowView(false);
   RemoveChildView(preview_);
   AddChildView(preview_);
   if (removed_shadow)  // Add back shadow view if it was removed.
     AddChildView(shadow_view_.get());
   Layout();
 }
 
+int ContentsContainer::preview_height() const {
+  return preview_ ? preview_->bounds().height() : 0;
+}
+
 void ContentsContainer::SetActiveTopMargin(int margin) {
   if (active_top_margin_ == margin)
     return;
 
   active_top_margin_ = margin;
   // Make sure we layout next time around. We need this in case our bounds
   // haven't changed.
   InvalidateLayout();
 }
 
@@ skipping 50 matching lines @@
 
   RemoveChildView(shadow_view_.get());
   if (delete_view)
     shadow_view_.reset(NULL);
   return true;
 }
 
 std::string ContentsContainer::GetClassName() const {
   return kViewClassName;
 }