Add initial support for handling touch events in desktop chrome AURA.

ui/views/win/hwnd_message_handler_delegate.h

Index: ui/views/win/hwnd_message_handler_delegate.h
===================================================================
--- ui/views/win/hwnd_message_handler_delegate.h	(revision 175450)
+++ ui/views/win/hwnd_message_handler_delegate.h	(working copy)
@@ -19,6 +19,7 @@
 class Accelerator;
 class KeyEvent;
 class MouseEvent;
+class TouchEvent;
 }
 
 namespace views {
@@ -171,6 +172,10 @@
   // translation). Returns true if the event was sent to the input method.
   virtual bool HandleUntranslatedKeyEvent(const ui::KeyEvent& event) = 0;
 
+  // Called when a touch event is received. Returns true if the event was
+  // handled by the delegate.
+  virtual bool HandleTouchEvent(const ui::TouchEvent& event) = 0;
+
   // Called when an IME message needs to be processed by the delegate. Returns
   // true if the event was handled and no default processing should be
   // performed.