Force touch events to be dispatched on FNL

ui/ozone/platform/drm/host/drm_window_host.cc

 // Copyright 2014 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/ozone/platform/drm/host/drm_window_host.h"
 
 #include "base/bind.h"
 #include "ui/events/devices/device_data_manager.h"
 #include "ui/events/event.h"
 #include "ui/events/ozone/evdev/event_factory_evdev.h"
@@ skipping 110 matching lines @@
 bool DrmWindowHost::CanDispatchEvent(const PlatformEvent& ne) {
   DCHECK(ne);
   Event* event = static_cast<Event*>(ne);
 
   // If there is a grab, capture events here.
   gfx::AcceleratedWidget grabber = window_manager_->event_grabber();
   if (grabber != gfx::kNullAcceleratedWidget)
     return grabber == widget_;
 
   if (event->IsTouchEvent()) {
+#ifdef FORCE_DISPATCH_TOUCH_EVENTS
+    // TODO(lanechr): This bypasses checks that ensure that touch events
+    // are dispatched to the right display.  The "right display" is defined as
+    // "the display associated with the touch device."  Displays are associated
+    // with touch devices through DeviceDataManager::UpdateTouchInfoForDisplay,

[jamesr, 2015/12/01 23:25:21]

wouldn't we call this from
https://github.com/domokit/mojo/blob/master/services/native_viewport/ozone/di...
if we want to assume that all displays can handle touch input?

+    // which (as of today) is never called.
+    //
+    // I'm not sure yet how to best determine touchscreen/display association,
+    // but FNL currently only supports devices with one touch screen.  So for
+    // now, always dispatch touch events on FNL devices.
+    return true;
+#endif
     // Dispatch the event if it is from the touchscreen associated with the
     // DrmWindowHost. We cannot check the event's location because if the
     // touchscreen has a bezel, touches in the bezel have a location outside of
     // |bounds_|.
     int64_t display_id =
         DeviceDataManager::GetInstance()->GetTargetDisplayForTouchDevice(
             event->source_device_id());
 
     if (display_id == gfx::Display::kInvalidDisplayID)
       return false;
@@ skipping 45 matching lines @@
 }
 
 void DrmWindowHost::SendBoundsChange() {
   // Update the cursor before the window so that the cursor stays within the
   // window bounds when the window size shrinks.
   cursor_->CommitBoundsChange(widget_, bounds_, GetCursorConfinedBounds());
   sender_->WindowBoundsChanged(widget_, bounds_);
 }
 
 }  // namespace ui