Add support for reposting the ET_GESTURE_TAP_DOWN gesture event to the RootWindow and in the

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"
@@ skipping 2023 matching lines @@
   }
 }
 
 void HWNDMessageHandler::OnThemeChanged() {
   ui::NativeThemeWin::instance()->CloseHandles();
 }
 
 LRESULT HWNDMessageHandler::OnTouchEvent(UINT message,
                                          WPARAM w_param,
                                          LPARAM l_param) {
+  // Handle touch events only on Aura for now.

[sky, 2013/08/22 22:07:16]

How does this effect non-aura?

[ananta, 2013/08/22 22:48:15]

In non AURA the RenderWidgetHostViewWin class handles touch events. 
Other widgets probably rely on the synthesized mouse events.

+#if !defined(USE_AURA)
+  SetMsgHandled(FALSE);
+  return 0;
+#endif
   int num_points = LOWORD(w_param);
   scoped_ptr<TOUCHINPUT[]> input(new TOUCHINPUT[num_points]);
   if (ui::GetTouchInputInfoWrapper(reinterpret_cast<HTOUCHINPUT>(l_param),
                                    num_points, input.get(),
                                    sizeof(TOUCHINPUT))) {
+    TouchEvents touch_events;
     for (int i = 0; i < num_points; ++i) {
       ui::EventType touch_event_type = ui::ET_UNKNOWN;
 
       if (input[i].dwFlags & TOUCHEVENTF_DOWN) {
         touch_ids_.insert(input[i].dwID);
         touch_event_type = ui::ET_TOUCH_PRESSED;
       } else if (input[i].dwFlags & TOUCHEVENTF_UP) {
         touch_ids_.erase(input[i].dwID);
         touch_event_type = ui::ET_TOUCH_RELEASED;
       } else if (input[i].dwFlags & TOUCHEVENTF_MOVE) {
         touch_event_type = ui::ET_TOUCH_MOVED;
       }
-      // Handle touch events only on Aura for now.
-#if defined(USE_AURA)
       if (touch_event_type != ui::ET_UNKNOWN) {
         POINT point;
         point.x = TOUCH_COORD_TO_PIXEL(input[i].x) /
             ui::win::GetUndocumentedDPIScale();
         point.y = TOUCH_COORD_TO_PIXEL(input[i].y) /
             ui::win::GetUndocumentedDPIScale();
 
         ScreenToClient(hwnd(), &point);
 
         ui::TouchEvent event(
             touch_event_type,
             gfx::Point(point.x, point.y),
             input[i].dwID % ui::GestureSequence::kMaxGesturePoints,
             base::TimeDelta::FromMilliseconds(input[i].dwTime));
-        delegate_->HandleTouchEvent(event);
+        touch_events.push_back(event);
       }
-#endif
     }
+    // Handle the touch events asynchronously. We need this because touch
+    // events on windows don't fire if we enter a modal loop in the context of
+    // a touch event.
+    base::MessageLoop::current()->PostTask(
+        FROM_HERE,
+        base::Bind(&HWNDMessageHandler::HandleTouchEvents,
+            base::Unretained(this), touch_events));

[sky, 2013/08/22 22:07:16]

Don't use Unretained here. There is no guarantee that 'this' won't be deleted
before HandleTouchEvents.

[ananta, 2013/08/22 22:48:15]

Done.

   }
   CloseTouchInputHandle(reinterpret_cast<HTOUCHINPUT>(l_param));
   SetMsgHandled(FALSE);
   return 0;
 }
 
 void HWNDMessageHandler::OnWindowPosChanging(WINDOWPOS* window_pos) {
   if (ignore_window_pos_changes_) {
     // If somebody's trying to toggle our visibility, change the nonclient area,
     // change our Z-order, or activate us, we should probably let it go through.
@@ skipping 83 matching lines @@
     MARGINS m = {10, 10, 10, 10};
     DwmExtendFrameIntoClientArea(hwnd(), &m);
   }
   if (window_pos->flags & SWP_SHOWWINDOW)
     delegate_->HandleVisibilityChanged(true);
   else if (window_pos->flags & SWP_HIDEWINDOW)
     delegate_->HandleVisibilityChanged(false);
   SetMsgHandled(FALSE);
 }
 
+void HWNDMessageHandler::HandleTouchEvents(const TouchEvents& touch_events) {
+  if (!delegate_)
+    return;
+  for (size_t i = 0; i < touch_events.size(); ++i) {

[sky, 2013/08/22 22:07:16]

nit: no {}

[ananta, 2013/08/22 22:48:15]

Done.

+    delegate_->HandleTouchEvent(touch_events[i]);
+  }
+}
+
 }  // namespace views