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

Add support for reposting the ET_GESTURE_TAP_DOWN gesture event to the RootWindow and in the 
corresponding function in the MenuController class.

This is on the same lines as posting the mouse down messages when we are exiting a menu
loop. In this case the user touches outside the menu bounds and the menu should abort while
reposting the gesture to the concerned window.

The other change is to process touch events in the HWNDMessageHandler class asynchronously as we don't
receive touch events if a modal loop is entered in the context of a touch message. Appears to be a bug
in Windows.

BUG=277018
R=sky@chromium.org
TBR=sadrul

TEST=RepostTapdownGestureTest

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=219190

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

+sadrul as he knows more about touch than I.

https://codereview.chromium.org/22865036/diff/6001/ui/aura/root_window.cc
File ui/aura/root_window.cc (right):

https://codereview.chromium.org/22865036/diff/6001/ui/aura/root_window.cc#new...
ui/aura/root_window.cc:219: if (event.type() != ui::ET_MOUSE_PRESSED &&
I think this should just be a DCHECK. Also, document it in the header.

https://codereview.chromium.org/22865036/diff/6001/ui/aura/root_window.cc#new...
ui/aura/root_window.cc:1038: if (old_consumer) {
nit: no {}

https://codereview.chromium.org/22865036/diff/6001/ui/views/controls/menu/men...
File ui/views/controls/menu/menu_controller.cc (right):

https://codereview.chromium.org/22865036/diff/6001/ui/views/controls/menu/men...
ui/views/controls/menu/menu_controller.cc:2132: if (target_root) {
nit: no {}

https://codereview.chromium.org/22865036/diff/6001/ui/views/win/hwnd_message_...
File ui/views/win/hwnd_message_handler.cc (right):

https://codereview.chromium.org/22865036/diff/6001/ui/views/win/hwnd_message_...
ui/views/win/hwnd_message_handler.cc:2044: // Handle touch events only on Aura
for now.
How does this effect non-aura?

https://codereview.chromium.org/22865036/diff/6001/ui/views/win/hwnd_message_...
ui/views/win/hwnd_message_handler.cc:2090: base::Unretained(this),
touch_events));
Don't use Unretained here. There is no guarantee that 'this' won't be deleted
before HandleTouchEvents.

https://codereview.chromium.org/22865036/diff/6001/ui/views/win/hwnd_message_...
ui/views/win/hwnd_message_handler.cc:2197: for (size_t i = 0; i <
touch_events.size(); ++i) {
nit: no {}

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

https://codereview.chromium.org/22865036/diff/6001/ui/aura/root_window.cc
File ui/aura/root_window.cc (right):

https://codereview.chromium.org/22865036/diff/6001/ui/aura/root_window.cc#new...
ui/aura/root_window.cc:219: if (event.type() != ui::ET_MOUSE_PRESSED &&
On 2013/08/22 22:07:16, sky wrote:
> I think this should just be a DCHECK. Also, document it in the header.

Done.

https://codereview.chromium.org/22865036/diff/6001/ui/aura/root_window.cc#new...
ui/aura/root_window.cc:1038: if (old_consumer) {
On 2013/08/22 22:07:16, sky wrote:
> nit: no {}

Done.

https://codereview.chromium.org/22865036/diff/6001/ui/views/controls/menu/men...
File ui/views/controls/menu/menu_controller.cc (right):

https://codereview.chromium.org/22865036/diff/6001/ui/views/controls/menu/men...
ui/views/controls/menu/menu_controller.cc:2132: if (target_root) {
On 2013/08/22 22:07:16, sky wrote:
> nit: no {}

Done.

https://codereview.chromium.org/22865036/diff/6001/ui/views/win/hwnd_message_...
File ui/views/win/hwnd_message_handler.cc (right):

https://codereview.chromium.org/22865036/diff/6001/ui/views/win/hwnd_message_...
ui/views/win/hwnd_message_handler.cc:2044: // Handle touch events only on Aura
for now.
On 2013/08/22 22:07:16, sky wrote:
> How does this effect non-aura?

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

https://codereview.chromium.org/22865036/diff/6001/ui/views/win/hwnd_message_...
ui/views/win/hwnd_message_handler.cc:2090: base::Unretained(this),
touch_events));
On 2013/08/22 22:07:16, sky wrote:
> Don't use Unretained here. There is no guarantee that 'this' won't be deleted
> before HandleTouchEvents.

Done.

https://codereview.chromium.org/22865036/diff/6001/ui/views/win/hwnd_message_...
ui/views/win/hwnd_message_handler.cc:2197: for (size_t i = 0; i <
touch_events.size(); ++i) {
On 2013/08/22 22:07:16, sky wrote:
> nit: no {}

Done.

[sky, 2013-08-22 23:28:29]

LGTM

[ananta, 2013-08-23 02:22:37]

TBR'ing sadrul. Will address comments in a followup.

[ananta, 2013-08-23 02:23:18]

Committed patchset #5 manually as r219190 (presubmit successful).

[sadrul, 2013-08-23 03:16:02]

https://codereview.chromium.org/22865036/diff/38001/ui/aura/root_window.cc
File ui/aura/root_window.cc (right):

https://codereview.chromium.org/22865036/diff/38001/ui/aura/root_window.cc#ne...
ui/aura/root_window.cc:232: held_repostable_event_.reset(new ui::GestureEvent(
Can you use 'new ui::GestureEvent(event, event.target(), this)' here? That would
be more like the code above used for MouseEvent (and it wouldn't be necessary to
expose GestureEvent::touch_ids_bitfield())

https://codereview.chromium.org/22865036/diff/38001/ui/aura/root_window.cc#ne...
ui/aura/root_window.cc:1038: Window* new_consumer =
GetEventHandlerForPoint(event->root_location());
This code should dispatch a GESTURE_BEGIN event before the TAP_DOWN, because
some code may depend on that behaviour.

https://codereview.chromium.org/22865036/diff/38001/ui/aura/root_window.h
File ui/aura/root_window.h (right):

https://codereview.chromium.org/22865036/diff/38001/ui/aura/root_window.h#new...
ui/aura/root_window.h:405: bool DispatchGestureEventRepost(ui::GestureEvent*
event);
I would move this up, just below DispatchTouchEventImpl()

https://codereview.chromium.org/22865036/diff/38001/ui/aura/root_window_unitt...
File ui/aura/root_window_unittest.cc (right):

https://codereview.chromium.org/22865036/diff/38001/ui/aura/root_window_unitt...
ui/aura/root_window_unittest.cc:908: filter->events().clear();
An interesting test would be to generate a Tap, or a Scroll gesture using
EventGenerator, in a way that the Window that receives the TAP_DOWN does a
repost. The test would verify that after TAP_DOWN is reposted, the rest of the
events (i.e. TAP, or SCROLL_BEGIN etc.) go to the new target.