Clip constrained windows to the tabcontents bounds.

chrome/browser/ui/views/tab_contents/native_tab_contents_view_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 "chrome/browser/ui/views/tab_contents/native_tab_contents_view_aura.h"
 
 #include "base/event_types.h"
 #include "base/message_loop.h"
 #include "chrome/browser/ui/sad_tab_helper.h"
 #include "chrome/browser/ui/tab_contents/tab_contents_wrapper.h"
 #include "chrome/browser/ui/views/tab_contents/native_tab_contents_view_delegate.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/render_widget_host_view.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_view.h"
 #include "ui/aura/client/drag_drop_client.h"
 #include "ui/aura/client/drag_drop_delegate.h"
 #include "ui/aura/event.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/window.h"
 #include "ui/base/dragdrop/drag_drop_types.h"
 #include "ui/base/dragdrop/os_exchange_data.h"
 #include "ui/base/dragdrop/os_exchange_data_provider_aura.h"
+#include "ui/gfx/compositor/layer.h"
 #include "ui/views/views_delegate.h"
 #include "ui/views/widget/widget.h"
 #include "webkit/glue/webdropdata.h"
 
 #if defined(USE_ASH)
 #include "ash/shell.h"
 #include "ash/wm/visibility_controller.h"
 #endif
 
 using content::RenderViewHost;
@@ skipping 122 matching lines @@
 
 void NativeTabContentsViewAura::InitNativeTabContentsView() {
   views::Widget::InitParams params(views::Widget::InitParams::TYPE_CONTROL);
   params.native_widget = this;
   // We don't draw anything so we don't need a texture.
   params.create_texture_for_layer = false;
   params.ownership = views::Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
   params.parent = NULL;
   params.can_activate = true;
   GetWidget()->Init(params);
+  GetNativeView()->layer()->SetMasksToBounds(true);
   GetNativeWindow()->SetName("NativeTabContentsViewAura");
 #if defined(USE_ASH)
   ash::SetChildWindowVisibilityChangesAnimated(GetWidget()->GetNativeView());
 #else
   NOTIMPLEMENTED() << "Need to animate in";
 #endif
 
   // Hide the widget to prevent it from showing up on the root window. This is
   // needed for TabContentses that aren't immediately added to the tabstrip,
   // e.g. the Instant preview contents.
@@ skipping 162 matching lines @@
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // NativeTabContentsView, public:
 
 // static
 NativeTabContentsView* NativeTabContentsView::CreateNativeTabContentsView(
     internal::NativeTabContentsViewDelegate* delegate) {
   return new NativeTabContentsViewAura(delegate);
 }