Allow form inputs to be potential cluster roots.

Source/core/rendering/FastTextAutosizer.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 140 matching lines @@
     //   consistent, unless they are floating or position:absolute/fixed.
     Node* node = renderer->generatingNode();
     if (node && !node->hasChildren())
         return false;
     if (!renderer->isRenderBlock())
         return false;
     if (renderer->isInline() && !renderer->style()->isDisplayReplacedType())
         return false;
     if (renderer->isListItem())
         return (renderer->isFloating() || renderer->isOutOfFlowPositioned());
-    // Avoid creating containers for text within form input.
-    if (isNonTextAreaFormControl(renderer->parent()))
-        return false;
 
     return true;
 }
 
 static bool isIndependentDescendant(const RenderBlock* renderer)
 {
     ASSERT(isPotentialClusterRoot(renderer));
 
     RenderBlock* containingBlock = renderer->containingBlock();
     return renderer->isRenderView()
@@ skipping 953 matching lines @@
 FastTextAutosizer::DeferUpdatePageInfo::~DeferUpdatePageInfo()
 {
     if (FastTextAutosizer* textAutosizer = m_mainFrame->document()->fastTextAutosizer()) {
         ASSERT(textAutosizer->m_updatePageInfoDeferred);
         textAutosizer->m_updatePageInfoDeferred = false;
         textAutosizer->updatePageInfoInAllFrames();
     }
 }
 
 } // namespace WebCore