Give up focus if the focused view becomes unfocusable

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 "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 43 matching lines @@
       orientation_(orientation),
       value_(0.f),
       keyboard_increment_(0.1f),
       animating_value_(0.f),
       value_is_valid_(false),
       accessibility_events_enabled_(true),
       focus_border_color_(0),
       bar_active_images_(kBarImagesActive),
       bar_disabled_images_(kBarImagesDisabled) {
   EnableCanvasFlippingForRTLUI(true);
-  set_focusable(true);
+  SetFocusable(true);
   UpdateState(true);
 }
 
 Slider::~Slider() {
 }
 
 void Slider::SetValue(float value) {
   SetValueInternal(value, VALUE_CHANGED_BY_API);
 }
 
@@ skipping 249 matching lines @@
 }
 
 void Slider::GetAccessibleState(ui::AccessibleViewState* state) {
   state->role = ui::AccessibilityTypes::ROLE_SLIDER;
   state->name = accessible_name_;
   state->value = UTF8ToUTF16(
       base::StringPrintf("%d%%", (int)(value_ * 100 + 0.5)));
 }
 
 }  // namespace views