Double clicking the resize handle should expand window along that axis.

ui/aura/test/test_window_delegate.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/aura/test/test_window_delegate.h"
 
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "ui/aura/event.h"
 #include "ui/aura/window.h"
 #include "ui/base/hit_test.h"
 #include "ui/gfx/canvas.h"
 
 namespace aura {
 namespace test {
 
 ////////////////////////////////////////////////////////////////////////////////
 // TestWindowDelegate
 
-TestWindowDelegate::TestWindowDelegate() {
+TestWindowDelegate::TestWindowDelegate() : window_component_(HTCLIENT) {
 }
 
 TestWindowDelegate::~TestWindowDelegate() {
 }
 
 gfx::Size TestWindowDelegate::GetMinimumSize() const {
   return gfx::Size();
 }
 
 void TestWindowDelegate::OnBoundsChanged(const gfx::Rect& old_bounds,
                                          const gfx::Rect& new_bounds) {
 }
 
 void TestWindowDelegate::OnFocus() {
 }
 
 void TestWindowDelegate::OnBlur() {
 }
 
 bool TestWindowDelegate::OnKeyEvent(KeyEvent* event) {
   return false;
 }
 
 gfx::NativeCursor TestWindowDelegate::GetCursor(const gfx::Point& point) {
   return gfx::kNullCursor;
 }
 
 int TestWindowDelegate::GetNonClientComponent(const gfx::Point& point) const {
-  return HTCLIENT;
+  return window_component_;
 }
 
 bool TestWindowDelegate::OnMouseEvent(MouseEvent* event) {
   return false;
 }
 
 ui::TouchStatus TestWindowDelegate::OnTouchEvent(TouchEvent* event) {
   return ui::TOUCH_STATUS_UNKNOWN;
 }
 
@@ skipping 37 matching lines @@
 }
 void ColorTestWindowDelegate::OnWindowDestroyed() {
   delete this;
 }
 void ColorTestWindowDelegate::OnPaint(gfx::Canvas* canvas) {
   canvas->GetSkCanvas()->drawColor(color_, SkXfermode::kSrc_Mode);
 }
 
 }  // namespace test
 }  // namespace aura