Support multi touch on Windows 8 AURA and ASH.

ui/views/win/hwnd_message_handler.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/views/win/hwnd_message_handler.h"
 
 #include <dwmapi.h>
 #include <shellapi.h>
 
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
 #include "base/win/windows_version.h"
 #include "ui/base/events/event.h"
 #include "ui/base/events/event_utils.h"
+#include "ui/base/gestures/gesture_sequence.h"
 #include "ui/base/keycodes/keyboard_code_conversion_win.h"
 #include "ui/base/win/hwnd_util.h"
 #include "ui/base/win/mouse_wheel_util.h"
 #include "ui/base/win/shell.h"
 #include "ui/base/win/touch_input.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/canvas_skia_paint.h"
 #include "ui/gfx/icon_util.h"
 #include "ui/gfx/insets.h"
 #include "ui/gfx/path.h"
@@ skipping 260 matching lines @@
   }
 
   return false;
 }
 
 #endif
 
 // The thickness of an auto-hide taskbar in pixels.
 const int kAutoHideTaskbarThicknessPx = 2;
 
-// The touch id to be used for touch events coming in from Windows Aura
-// Desktop.
-const int kDesktopChromeAuraTouchId = 9;
-
 // For windows with the standard frame removed, the client area needs to be
 // different from the window area to avoid a "feature" in Windows's handling of
 // WM_NCCALCSIZE data. See the comment near the bottom of GetClientAreaInsets
 // for more details.
 const int kClientAreaBottomInsetHack = -1;
 
 }  // namespace
 
 // A scoping class that prevents a window from being able to redraw in response
 // to invalidations that may occur within it for the lifetime of the object.
@@ skipping 1687 matching lines @@
       if (touch_event_type != ui::ET_UNKNOWN) {
         POINT point;
         point.x = TOUCH_COORD_TO_PIXEL(input[i].x);
         point.y = TOUCH_COORD_TO_PIXEL(input[i].y);
 
         ScreenToClient(hwnd(), &point);
 
         ui::TouchEvent event(
             touch_event_type,
             gfx::Point(point.x, point.y),
-            kDesktopChromeAuraTouchId,
+            input[i].dwID % ui::GestureSequence::kMaxGesturePoints,
             base::TimeDelta::FromMilliseconds(input[i].dwTime));
         delegate_->HandleTouchEvent(event);
       }
 #endif
     }
   }
   CloseTouchInputHandle(reinterpret_cast<HTOUCHINPUT>(l_param));
   SetMsgHandled(FALSE);
   return 0;
 }
@@ skipping 83 matching lines @@
     DwmExtendFrameIntoClientArea(hwnd(), &m);
   }
   if (window_pos->flags & SWP_SHOWWINDOW)
     delegate_->HandleVisibilityChanged(true);
   else if (window_pos->flags & SWP_HIDEWINDOW)
     delegate_->HandleVisibilityChanged(false);
   SetMsgHandled(FALSE);
 }
 
 }  // namespace views