Add multi-finger swipe detection to GestureDetector

ui/events/gesture_detection/mock_motion_event.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/mock_motion_event.h"
 
 #include "base/logging.h"
 
 using base::TimeTicks;
 
@@ skipping 20 matching lines @@
                                  TimeTicks time,
                                  float x0,
                                  float y0,
                                  float x1,
                                  float y1)
     : action(action), pointer_count(2), time(time), id(0) {
   points[0].SetPoint(x0, y0);
   points[1].SetPoint(x1, y1);
 }
 
+MockMotionEvent::MockMotionEvent(Action action,
+                                 TimeTicks time,
+                                 float x0,
+                                 float y0,
+                                 float x1,
+                                 float y1,
+                                 float x2,
+                                 float y2)
+    : action(action), pointer_count(3), time(time), id(0) {
+  points[0].SetPoint(x0, y0);
+  points[1].SetPoint(x1, y1);
+  points[2].SetPoint(x2, y2);
+}
+
 MockMotionEvent::MockMotionEvent(const MockMotionEvent& other)
     : action(other.action),
       pointer_count(other.pointer_count),
       time(other.time),
       id(other.GetId()) {
   points[0] = other.points[0];
   points[1] = other.points[1];
 }
 
 MockMotionEvent::~MockMotionEvent() {}
@@ skipping 97 matching lines @@
 }
 
 void MockMotionEvent::CancelPoint() {
   DCHECK_GT(pointer_count, 0U);
   if (pointer_count > 1)
     --pointer_count;
   action = ACTION_CANCEL;
 }
 
 }  // namespace ui