MacViews: Implement Full Keyboard Access.

ui/views/controls/button/label_button.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/button/label_button.h"
 
 #include <stddef.h>
 
 #include <utility>
 
@@ skipping 177 matching lines @@
   // All callers currently pass STYLE_BUTTON, and should only call this once, to
   // change from the default style.
   DCHECK_EQ(style, STYLE_BUTTON);
   DCHECK_EQ(style_, STYLE_TEXTBUTTON);
   DCHECK(!GetWidget()) << "Can't change button style after adding to a Widget.";
 
   style_ = style;
 
   SetFocusPainter(nullptr);
   SetHorizontalAlignment(gfx::ALIGN_CENTER);
+
+#if !defined(OS_MACOSX)
   SetFocusable(true);
+#else
+  SetFocusable(false);
+  SetAccessibilityFocusable(true);
+#endif
+
   SetMinSize(gfx::Size(70, 33));
 
   // Themed borders will be set once the button is added to a Widget, since that
   // provides the value of GetNativeTheme().
 }
 
 void LabelButton::SetImageLabelSpacing(int spacing) {
   if (spacing == image_label_spacing_)
     return;
   image_label_spacing_ = spacing;
@@ skipping 295 matching lines @@
   GetExtraParams(params);
   return ui::NativeTheme::kHovered;
 }
 
 void LabelButton::ResetCachedPreferredSize() {
   cached_preferred_size_valid_ = false;
   cached_preferred_size_ = gfx::Size();
 }
 
 }  // namespace views