Expose double-tap platform support via ui::GestureConfiguration

ui/events/gesture_detection/gesture_provider.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/events/gesture_detection/gesture_provider.h"
 
 #include <cmath>
 
 #include "base/auto_reset.h"
 #include "base/debug/trace_event.h"
@@ skipping 47 matching lines @@
       center.x() - width / 2.f, center.y() - height / 2.f, width, height);
 }
 
 }  // namespace
 
 // GestureProvider:::Config
 
 GestureProvider::Config::Config()
     : display(gfx::Display::kInvalidDisplayID, gfx::Rect(1, 1)),
       disable_click_delay(false),
+      double_tap_support_for_platform_enabled(true),
       gesture_begin_end_types_enabled(false),
       min_gesture_bounds_length(0),
       max_gesture_bounds_length(0) {
 }
 
 GestureProvider::Config::~Config() {
 }
 
 // GestureProvider::GestureListener
 
@@ skipping 595 matching lines @@
   bool show_press_event_sent_;
 
   DISALLOW_COPY_AND_ASSIGN(GestureListenerImpl);
 };
 
 // GestureProvider
 
 GestureProvider::GestureProvider(const Config& config,
                                  GestureProviderClient* client)
     : double_tap_support_for_page_(true),
-      double_tap_support_for_platform_(true),
+      double_tap_support_for_platform_(
+          config.double_tap_support_for_platform_enabled),
       gesture_begin_end_types_enabled_(config.gesture_begin_end_types_enabled) {
   DCHECK(client);
   DCHECK(!config.min_gesture_bounds_length ||
          !config.max_gesture_bounds_length ||
          config.min_gesture_bounds_length <= config.max_gesture_bounds_length);
   TRACE_EVENT0("input", "GestureProvider::InitGestureDetectors");
   gesture_listener_.reset(new GestureListenerImpl(config, client));
   UpdateDoubleTapDetectionSupport();
 }
 
@@ skipping 127 matching lines @@
   // null'ing of the listener until the sequence has ended.
   if (current_down_event_)
     return;
 
   const bool double_tap_enabled =
       double_tap_support_for_page_ && double_tap_support_for_platform_;
   gesture_listener_->SetDoubleTapEnabled(double_tap_enabled);
 }
 
 }  //  namespace ui