Ensure we never remove the style attribute when syncing it from CSSOM.

third_party/WebKit/Source/core/dom/Element.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Peter Kelly (pmk@post.com)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2013 Apple Inc.
  * All rights reserved.
  *           (C) 2007 Eric Seidel (eric@webkit.org)
  *
@@ skipping 3998 matching lines @@
 }
 
 void Element::SynchronizeStyleAttributeInternal() const {
   DCHECK(IsStyledElement());
   DCHECK(GetElementData());
   DCHECK(GetElementData()->style_attribute_is_dirty_);
   GetElementData()->style_attribute_is_dirty_ = false;
   const StylePropertySet* inline_style = this->InlineStyle();
   const_cast<Element*>(this)->SetSynchronizedLazyAttribute(
       styleAttr,
-      inline_style ? AtomicString(inline_style->AsText()) : g_null_atom);
+      inline_style ? AtomicString(inline_style->AsText()) : g_empty_atom);
 }
 
 CSSStyleDeclaration* Element::style() {
   if (!IsStyledElement())
     return nullptr;
   return &EnsureElementRareData().EnsureInlineCSSStyleDeclaration(this);
 }
 
 StylePropertyMap* Element::styleMap() {
   if (!IsStyledElement())
@@ skipping 306 matching lines @@
 }
 
 DEFINE_TRACE_WRAPPERS(Element) {
   if (HasRareData()) {
     visitor->TraceWrappers(GetElementRareData());
   }
   ContainerNode::TraceWrappers(visitor);
 }
 
 }  // namespace blink