MacViews: Implement Full Keyboard Access.

ui/views/controls/combobox/combobox.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/combobox/combobox.h"
 
 #include <stddef.h>
 
 #include <utility>
 
@@ skipping 73 matching lines @@
 const int kFocusedPressedMenuButtonImages[] =
     MENU_IMAGE_GRID(IDR_COMBOBOX_BUTTON_F_P);
 
 #undef MENU_IMAGE_GRID
 
 // The transparent button which holds a button state but is not rendered.
 class TransparentButton : public CustomButton {
  public:
   TransparentButton(ButtonListener* listener)
       : CustomButton(listener) {
+    SetAccessibilityFocusable(false);

[tapted, 2016/02/12 02:56:44]

perhaps DCHECK(!IsFocusable());  after this? It's subtle that LabelButtons are
by-default focusable, but not CustomButtons

[karandeepb, 2016/02/22 07:15:37]

Done.

     SetAnimationDuration(LabelButton::kHoverAnimationDurationMs);
   }
   ~TransparentButton() override {}
 
   bool OnMousePressed(const ui::MouseEvent& mouse_event) override {
     parent()->RequestFocus();
     return true;
   }
 
   double GetAnimationValue() const {
@@ skipping 239 matching lines @@
     : model_(model),
       style_(STYLE_NORMAL),
       listener_(NULL),
       selected_index_(model_->GetDefaultIndex()),
       invalid_(false),
       menu_model_adapter_(new ComboboxMenuModelAdapter(this, model)),
       text_button_(new TransparentButton(this)),
       arrow_button_(new TransparentButton(this)),
       weak_ptr_factory_(this) {
   ModelChanged();
+
+#if !defined(OS_MACOSX)
   SetFocusable(true);
+#else
+  SetFocusable(false);
+  SetAccessibilityFocusable(true);
+#endif
+
   UpdateBorder();
 
   // Initialize the button images.
   Button::ButtonState button_states[] = {
     Button::STATE_DISABLED,
     Button::STATE_NORMAL,
     Button::STATE_HOVERED,
     Button::STATE_PRESSED,
   };
   for (int i = 0; i < 2; i++) {
     for (size_t state_index = 0; state_index < arraysize(button_states);
          state_index++) {
       Button::ButtonState state = button_states[state_index];
       size_t num;
       bool focused = !!i;
       const int* ids = GetBodyButtonImageIds(focused, state, &num);
       body_button_painters_[focused][state].reset(
           Painter::CreateImageGridPainter(ids));
       menu_button_images_[focused][state] = GetMenuButtonImages(focused, state);
     }
   }
 
   text_button_->SetVisible(true);
   arrow_button_->SetVisible(true);
-  text_button_->SetFocusable(false);
-  arrow_button_->SetFocusable(false);
   AddChildView(text_button_);
   AddChildView(arrow_button_);
 }
 
 Combobox::~Combobox() {
   if (GetInputMethod() && selector_.get()) {
     // Combobox should have been blurred before destroy.
     DCHECK(selector_.get() != GetInputMethod()->GetTextInputClient());
   }
 }
@@ skipping 536 matching lines @@
   return gfx::Size(width, font_list.GetHeight());
 }
 
 PrefixSelector* Combobox::GetPrefixSelector() {
   if (!selector_)
     selector_.reset(new PrefixSelector(this));
   return selector_.get();
 }
 
 }  // namespace views