Make it possible to focus on 0-size form controls and anchors.

Source/core/html/HTMLAnchorElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Simon Hausmann <hausmann@kde.org>
  * Copyright (C) 2003, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 145 matching lines @@
     // Links are focusable by default, but only allow links with tabindex or contenteditable to be mouse focusable.
     // https://bugs.webkit.org/show_bug.cgi?id=26856
     if (isLink())
         return HTMLElement::supportsFocus();
 
     return HTMLElement::isMouseFocusable();
 }
 
 bool HTMLAnchorElement::isKeyboardFocusable() const
 {
-    if (!isLink())
-        return HTMLElement::isKeyboardFocusable();
-
-    if (!isFocusable())
-        return false;
-
-    Page* page = document().page();
-    if (!page)
-        return false;
-
-    if (!page->chrome().client().tabsToLinks())
-        return false;
-
-    if (isInCanvasSubtree())
-        return true;
-
-    return hasNonEmptyBoundingBox();
+    if (isLink()) {
+        Page* page = document().page();
+        if (!page)
+            return false;
+        if (!page->chrome().client().tabsToLinks())
+            return false;
+    }
+    return HTMLElement::isKeyboardFocusable();
 }
 
 static void appendServerMapMousePosition(StringBuilder& url, Event* event)
 {
     if (!event->isMouseEvent())
         return;
 
     ASSERT(event->target());
     Node* target = event->target()->toNode();
     ASSERT(target);
@@ skipping 657 matching lines @@
 
     // The precision of current MouseOver trigger is too low to actually trigger preconnects.
     if (motivation == WebKit::WebPreconnectMotivationLinkMouseOver)
         return;
 
     preconnectToURL(url, motivation);
     m_hasIssuedPreconnect = true;
 }
 
 }