MacViews: Implement Full Keyboard Access.

chrome/browser/ui/views/toolbar/app_menu.cc

Index: chrome/browser/ui/views/toolbar/app_menu.cc
diff --git a/chrome/browser/ui/views/toolbar/app_menu.cc b/chrome/browser/ui/views/toolbar/app_menu.cc
index 5cee86832ae3396e4b4c76212220bbd13796c8b4..56ad5d1920c5318bf5a147078a67fafbf6db0765 100644
--- a/chrome/browser/ui/views/toolbar/app_menu.cc
+++ b/chrome/browser/ui/views/toolbar/app_menu.cc
@@ -284,7 +284,9 @@ class InMenuButton : public LabelButton {
   ~InMenuButton() override {}
 
   void Init(InMenuButtonBackground::ButtonType type) {
-    SetFocusable(true);
+    // An InMenuButton should always be focusable regardless of the platform.
+    // Hence we don't use Button::ConfigureDefaultFocus().
+    SetFocusBehavior(views::View::FocusBehavior::ALWAYS);
     set_request_focus_on_press(false);
     SetHorizontalAlignment(gfx::ALIGN_CENTER);
 
@@ -553,7 +555,9 @@ class AppMenu::ZoomView : public AppMenuView {
             IDR_FULLSCREEN_MENU_BUTTON);
     fullscreen_button_->SetImage(ImageButton::STATE_NORMAL, full_screen_image);
 
-    fullscreen_button_->SetFocusable(true);
+    // Since |fullscreen_button_| will reside in a menu, make it ALWAYS
+    // focusable regardless of the platform.
+    fullscreen_button_->SetFocusBehavior(views::View::FocusBehavior::ALWAYS);
     fullscreen_button_->set_request_focus_on_press(false);
     fullscreen_button_->set_tag(fullscreen_index);
     fullscreen_button_->SetImageAlignment(