Reenable the tap down gesture.

content/browser/android/content_view_core_impl.cc

 // Copyright 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 "content/browser/android/content_view_core_impl.h"
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_array.h"
 #include "base/android/jni_string.h"
 #include "base/android/scoped_java_ref.h"
@@ skipping 1043 matching lines @@
                                           jfloat x,
                                           jfloat y) {
   WebGestureEvent event = MakeGestureEvent(
       WebInputEvent::GestureTapCancel, time_ms, x, y);
   SendGestureEvent(event);
 }
 
 void ContentViewCoreImpl::TapDown(JNIEnv* env, jobject obj,
                                   jlong time_ms,
                                   jfloat x, jfloat y) {
-  // TODO - once Blink accepts tap down events correctly, fire tap down
-  // here. See crbug.com/302752.
+  WebGestureEvent event = MakeGestureEvent(
+      WebInputEvent::GestureTapDown, time_ms, x, y);
+  SendGestureEvent(event);
 }
 
 void ContentViewCoreImpl::DoubleTap(JNIEnv* env, jobject obj, jlong time_ms,
                                     jfloat x, jfloat y) {
   WebGestureEvent event = MakeGestureEvent(
       WebInputEvent::GestureDoubleTap, time_ms, x, y);
   SendGestureEvent(event);
 }
 
 void ContentViewCoreImpl::LongPress(JNIEnv* env, jobject obj, jlong time_ms,
@@ skipping 553 matching lines @@
       reinterpret_cast<ui::ViewAndroid*>(view_android),
       reinterpret_cast<ui::WindowAndroid*>(window_android));
   return reinterpret_cast<jint>(view);
 }
 
 bool RegisterContentViewCore(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace content