Support 3f swipe for tab scrubbing

ui/base/events/event.cc

 // Copyright (c) 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 "ui/base/events/event.h"
 
 #if defined(USE_X11)
 #include <X11/Xlib.h>
 #endif
 
@@ skipping 487 matching lines @@
       data_(data),
       source_operations_(source_operations) {
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // ScrollEvent
 
 ScrollEvent::ScrollEvent(const base::NativeEvent& native_event)
     : MouseEvent(native_event) {
   if (type() == ET_SCROLL) {
-    GetScrollOffsets(native_event, &x_offset_, &y_offset_);
+    GetScrollOffsets(native_event, &x_offset_, &y_offset_, &finger_count_);
     double start, end;
     GetGestureTimes(native_event, &start, &end);
   } else if (type() == ET_SCROLL_FLING_START) {
     bool is_cancel;
     GetFlingData(native_event, &x_offset_, &y_offset_, &is_cancel);
   }
 }
 
 ScrollEvent::ScrollEvent(EventType type,
                          const gfx::Point& location,
@@ skipping 27 matching lines @@
 int GestureEvent::GetLowestTouchId() const {
   if (touch_ids_bitfield_ == 0)
     return -1;
   int i = -1;
   // Find the index of the least significant 1 bit
   while (!(1 << ++i & touch_ids_bitfield_));
   return i;
 }
 
 }  // namespace ui