Fix index used to join results of DOM.getDocument and CSS.getLayoutTreeAndStyles

third_party/WebKit/Source/core/inspector/InspectorCSSAgent.h

 /*
  * Copyright (C) 2010, 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:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 314 matching lines @@
                                          VectorStringHashTraits,
                                          VectorStringHashTraits>;
 
   void visitLayoutTreeNodes(
       Node*,
       protocol::Array<protocol::CSS::LayoutTreeNode>& layoutTreeNodes,
       const Vector<std::pair<String, CSSPropertyID>>& cssPropertyWhitelist,
       ComputedStylesMap& styleToIndexMap,
       protocol::Array<protocol::CSS::ComputedStyle>& computedStyles);
 
+  // A non-zero index corresponds to a style in |computedStyles|, -1 means an
+  // empty style.
   int getStyleIndexForNode(
       Node*,
       const Vector<std::pair<String, CSSPropertyID>>& cssPropertyWhitelist,
       ComputedStylesMap& styleToIndexMap,
       protocol::Array<protocol::CSS::ComputedStyle>& computedStyles);
 
   Member<InspectorDOMAgent> m_domAgent;
   Member<InspectedFrames> m_inspectedFrames;
   Member<InspectorNetworkAgent> m_networkAgent;
   Member<InspectorResourceContentLoader> m_resourceContentLoader;
@@ skipping 16 matching lines @@
 
   int m_resourceContentLoaderClientId;
 
   friend class InspectorResourceContentLoaderCallback;
   friend class StyleSheetBinder;
 };
 
 }  // namespace blink
 
 #endif  // !defined(InspectorCSSAgent_h)