Reenable the tap down gesture.

content/browser/renderer_host/input/gesture_event_filter.cc

 // Copyright 2013 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 "content/browser/renderer_host/input/gesture_event_filter.h"
 
 #include "base/command_line.h"
 #include "base/strings/string_number_conversions.h"
 #include "content/browser/renderer_host/input/input_router.h"
 #include "content/browser/renderer_host/input/touchpad_tap_suppression_controller.h"
@@ skipping 350 matching lines @@
 
 void GestureEventFilter::SendEventsIgnoringAck() {
   GestureEventWithLatencyInfo gesture_event;
   while (!coalesced_gesture_events_.empty()) {
     gesture_event = coalesced_gesture_events_.front();
     if (!GestureEventFilter::ShouldIgnoreAckForGestureType(
             gesture_event.event.type)) {
       return;
     }
     coalesced_gesture_events_.pop_front();
-
-    // TODO - once Blink accepts tap down events correctly, re-enable tap
-    // down. See crbug.com/302752.
-    if (gesture_event.event.type == WebInputEvent::GestureTapDown)
-      continue;
-
     client_->SendGestureEventImmediately(gesture_event);
   }
 }
 
 bool GestureEventFilter::ShouldIgnoreAckForGestureType(
     WebInputEvent::Type type) {
   return type == WebInputEvent::GestureTapDown ||
       type == WebInputEvent::GestureShowPress;
 }
 
 }  // namespace content