Fix controlling volume slider with keyboard

ui/views/controls/slider.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/views/controls/slider.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 224 matching lines @@
 bool Slider::OnMouseDragged(const ui::MouseEvent& event) {
   MoveButtonTo(event.location());
   return true;
 }
 
 void Slider::OnMouseReleased(const ui::MouseEvent& event) {
   OnSliderDragEnded();
 }
 
 bool Slider::OnKeyPressed(const ui::KeyEvent& event) {
-  int new_value = value_;
+  float new_value = value_;
   if (event.key_code() == ui::VKEY_LEFT)
     new_value -= keyboard_increment_;
   else if (event.key_code() == ui::VKEY_RIGHT)
     new_value += keyboard_increment_;
   else
     return false;
   SetValueInternal(new_value, VALUE_CHANGED_BY_USER);
   return true;
 }
 
@@ skipping 47 matching lines @@
   if (listener_)
     listener_->SliderDragStarted(this);
 }
 
 void Slider::OnSliderDragEnded() {
   if (listener_)
     listener_->SliderDragEnded(this);
 }
 
 }  // namespace views