Add an adapter layer (WMHelper) between exo and ash.

components/exo/touch.cc

 // Copyright 2015 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 "components/exo/touch.h"
 
-#include "ash/shell.h"
 #include "components/exo/surface.h"
 #include "components/exo/touch_delegate.h"
+#include "components/exo/wm_helper.h"
 #include "ui/aura/window.h"
 #include "ui/events/event.h"
 
 namespace exo {
 namespace {
 
 // Helper function that returns an iterator to the first item in |vector|
 // with |value|.
 template <typename T, typename U>
 typename T::iterator FindVectorItem(T& vector, U value) {
   return std::find(vector.begin(), vector.end(), value);
 }
 
 // Helper function that returns true if |vector| contains an item with |value|.
 template <typename T, typename U>
 bool VectorContainsItem(T& vector, U value) {
   return FindVectorItem(vector, value) != vector.end();
 }
 
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
 // Touch, public:
 
 Touch::Touch(TouchDelegate* delegate) : delegate_(delegate) {
-  ash::Shell::GetInstance()->AddPreTargetHandler(this);
+  WMHelper::GetInstance()->AddPreTargetHandler(this);
 }
 
 Touch::~Touch() {
   delegate_->OnTouchDestroying(this);
   if (focus_)
     focus_->RemoveSurfaceObserver(this);
-  ash::Shell::GetInstance()->RemovePreTargetHandler(this);
+  WMHelper::GetInstance()->RemovePreTargetHandler(this);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // ui::EventHandler overrides:
 
 void Touch::OnTouchEvent(ui::TouchEvent* event) {
   switch (event->type()) {
     case ui::ET_TOUCH_PRESSED: {
       // Early out if event doesn't contain a valid target for touch device.
       Surface* target = GetEffectiveTargetForEvent(event);
@@ skipping 89 matching lines @@
 Surface* Touch::GetEffectiveTargetForEvent(ui::Event* event) const {
   Surface* target =
       Surface::AsSurface(static_cast<aura::Window*>(event->target()));
   if (!target)
     return nullptr;
 
   return delegate_->CanAcceptTouchEventsForSurface(target) ? target : nullptr;
 }
 
 }  // namespace exo