MacViews: Implement Full Keyboard Access.

ui/views/focus/focus_search.cc

Index: ui/views/focus/focus_search.cc
diff --git a/ui/views/focus/focus_search.cc b/ui/views/focus/focus_search.cc
index a7ede3b0bf3d044666fbcdb9df23a3d45017f57b..f4d77002f5885342c7c1fee32142ef6df74f7112 100644
--- a/ui/views/focus/focus_search.cc
+++ b/ui/views/focus/focus_search.cc
@@ -98,11 +98,15 @@ bool FocusSearch::IsViewFocusableCandidate(View* v, int skip_group_id) {
        v->GetGroup() != skip_group_id);
 }
 
+// On Mac, we also need to read system preferences for "Full Keyboard Access" to

[tapted, 2016/02/12 02:56:45]

Can we instead expose the |accessibility_mode_| data member?

Then BridgedNativeWidget can simply call
native_widget_mac_->GetWidget()->GetFocusSearch()->SetAccessibilityMode([NSApp
isFullKeyboardAccessEnabled]);

(probably at the end of SetRootView)

There also should be a system notification that we listen for when the user
presses Ctrl+F7, so that we can toggle this on the fly. SetAccessibilityMode(..)
should then advance focus if it's currently on a non-focusable view, to match
OSX behaviour.

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

Done. Instead of setting the accessibility mode on the FocusSearch, I am setting
it on the FocusManager. This is because, each widget in the widget hierarchy
will have its own separate FocusSearch (corresponding to its root view) but all
of them will have the same FocusManager.

+// decide whether accessibility mode should be enabled or not.
+#if !defined(OS_MACOSX)
 bool FocusSearch::IsFocusable(View* v) {
   if (accessibility_mode_)
     return v && v->IsAccessibilityFocusable();
   return v && v->IsFocusable();
 }
+#endif
 
 View* FocusSearch::FindSelectedViewForGroup(View* view) {
   if (view->IsGroupFocusTraversable() ||