Bound the maximum touchscreen fling velocity.

ui/base/gestures/gesture_sequence.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/gestures/gesture_sequence.h"
 
 #include <cmath>
 #include <stdlib.h>
 
 #include "base/logging.h"
@@ skipping 278 matching lines @@
   const unsigned last_coefficient =
       GestureConfiguration::NumAccelParams - 1;
   float normalized_velocity = fabs(velocity * kFlingCurveNormalization);
   float nu = 0.0f, x = 1.f;
 
   for (int i = last_coefficient ; i >= 0; i--) {
     float a = GestureConfiguration::fling_acceleration_curve_coefficients(i);
     nu += x * a;
     x *= normalized_velocity;
   }
-  return nu * velocity;
+  if (velocity < 0.f)
+    return std::max(nu * velocity, -GestureConfiguration::fling_velocity_cap());
+  else
+    return std::min(nu * velocity, GestureConfiguration::fling_velocity_cap());
 }
 
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
 // GestureSequence Public:
 
 GestureSequence::GestureSequence(GestureEventHelper* helper)
     : state_(GS_NO_GESTURE),
       flags_(0),
@@ skipping 812 matching lines @@
     return;
 
   // Since long press timer has been started, there should be a non-NULL point.
   const GesturePoint* point = GetPointByPointId(0);
   if (!ui::gestures::IsInsideManhattanSquare(point->first_touch_position(),
       event.location()))
     GetLongPressTimer()->Stop();
 }
 
 }  // namespace ui