Tweak touchpad settings for better performance.

chrome/browser/chromeos/touchpad.cc

 // Copyright (c) 2009 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 "chrome/browser/chromeos/touchpad.h"
 
 #include <stdlib.h>
 #include <string>
 #include <vector>
 
@@ skipping 86 matching lines @@
   // To disable vertical edge scroll, we set VertEdgeScroll to 0. Vertical edge
   // scroll lets you use the right edge of the touchpad to control the movement
   // of the vertical scroll bar.
   if (vert_edge_scroll_enabled_.GetValue())
     SetSynclientParam("VertEdgeScroll", 1);
   else
     SetSynclientParam("VertEdgeScroll", 0);
 }
 
 void Touchpad::SetSpeedFactor() {
-  // To set speed factor, we use MinSpeed. Both MaxSpeed and AccelFactor are 0.
-  // So MinSpeed will control the speed of the cursor with respect to the
-  // touchpad movement and there will not be any acceleration.
-  // MinSpeed is between 0.01 and 1.00. The preference is an integer between
-  // 1 and 10, so we divide that by 10 for the value of MinSpeed.
+  // To set speed factor, we use MaxSpeed. MinSpeed is set to 0.2.
+  // MaxSpeed can go from 0.2 to 1.1. The preference is an integer between
+  // 1 and 10, so we divide that by 10 and add 0.1 for the value of MaxSpeed.
   int value = speed_factor_.GetValue();
   if (value < 1)
     value = 1;
   if (value > 10)
     value = 10;
-  // Convert from 1-10 to 0.1-1.0
-  double d = static_cast<double>(value) / 10.0;
-  SetSynclientParam("MinSpeed", d);
+  // Convert from 1-10 to 0.2-1.1
+  double d = static_cast<double>(value) / 10.0 + 0.1;
+  SetSynclientParam("MaxSpeed", d);
 }
 
 void Touchpad::SetSensitivity() {
   // To set the touch sensitivity, we use FingerHigh, which represents the
   // the pressure needed for a tap to be registered. The range of FingerHigh
   // goes from 25 to 70. We store the sensitivity preference as an int from
   // 1 to 10. So we need to map the preference value of 1 to 10 to the
   // FingerHigh value of 25 to 70 inversely.
   int value = sensitivity_.GetValue();
   if (value < 1)
     value = 1;
   if (value > 10)
     value = 10;
   // Convert from 1-10 to 70-25.
   double d = (15 - value) * 5;
   SetSynclientParam("FingerHigh", d);
 }