Indicate focused state on text buttons with blue outline.

ui/base/native_theme/native_theme.h

 // 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.
 
 #ifndef UI_BASE_NATIVE_THEME_NATIVE_THEME_H_
 #define UI_BASE_NATIVE_THEME_NATIVE_THEME_H_
 #pragma once
 
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/base/ui_export.h"
@@ skipping 75 matching lines @@
     kMaxState,
   };
 
   // Each structure below holds extra information needed when painting a given
   // part.
 
   struct ButtonExtraParams {
     bool checked;
     bool indeterminate;  // Whether the button state is indeterminate.
     bool is_default;  // Whether the button is default button.
+    bool is_focused;
     bool has_border;
     int classic_state;  // Used on Windows when uxtheme is not available.
     SkColor background_color;
   };
 
   struct InnerSpinButtonExtraParams {
     bool spin_up;
     bool read_only;
     int classic_state;  // Used on Windows when uxtheme is not available.
   };
@@ skipping 158 matching lines @@
   static unsigned int thumb_inactive_color_;
   static unsigned int thumb_active_color_;
   static unsigned int track_color_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeTheme);
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_NATIVE_THEME_NATIVE_THEME_H_