MacViews: Implement Full Keyboard Access.

ui/views/cocoa/views_nswindow_delegate.mm

Index: ui/views/cocoa/views_nswindow_delegate.mm
diff --git a/ui/views/cocoa/views_nswindow_delegate.mm b/ui/views/cocoa/views_nswindow_delegate.mm
index 75346a6a8076dadb929abc2f858e5a2cf57e6892..18a8703479ad630a998a38cf1e11dd5da4b3b396 100644
--- a/ui/views/cocoa/views_nswindow_delegate.mm
+++ b/ui/views/cocoa/views_nswindow_delegate.mm
@@ -43,6 +43,13 @@
   parent_->OnVisibilityChanged();
 }
 
+- (void)onFullKeyboardAccessModeChanged:(NSNotification*)notification {
+  parent_->native_widget_mac()

[tapted, 2016/02/23 03:01:19]

I think nicer would be a new method on BridgedContentView, perhaps
`UpdateFullKeyboardAccess()` (i.e. rather than On...Changed, since we want to
call it when we don't know if it's changing).

Then collapse all the places you have a `[NSApp isFullKeyboardAccessEnabled]`
into that single function.

[karandeepb, 2016/03/15 02:19:50]

Done.

+      ->GetWidget()
+      ->GetFocusManager()
+      ->SetKeyboardAccessibility([NSApp isFullKeyboardAccessEnabled]);
+}
+
 - (void)onWindowWillDisplay {
   parent_->OnVisibilityChangedTo(true);
 }