Update ThreatDOMDetails to be able to collect non-resource HTML Elements based on their attributes.

chrome/renderer/safe_browsing/threat_dom_details.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // ThreatDOMDetails iterates over a document's frames and gathers
 // interesting URLs such as those of scripts and frames. When done, it sends
 // them to the ThreatDetails that requested them.
 
 #ifndef CHROME_RENDERER_SAFE_BROWSING_THREAT_DOM_DETAILS_H_
 #define CHROME_RENDERER_SAFE_BROWSING_THREAT_DOM_DETAILS_H_
 
 #include <vector>
 
 #include "base/compiler_specific.h"
+#include "base/feature_list.h"
 #include "content/public/renderer/render_frame_observer.h"
 
 struct SafeBrowsingHostMsg_ThreatDOMDetails_Node;
 
 namespace safe_browsing {
 
+extern const base::Feature kThreatDomDetailsTagAndAttributeFeature;
+extern const char kTagAndAttributeParamName[];
+
 // There is one ThreatDOMDetails per RenderFrame.
 class ThreatDOMDetails : public content::RenderFrameObserver {
  public:
   // An upper limit on the number of nodes we collect. Not const for the test.
   static uint32_t kMaxNodes;
 
   static ThreatDOMDetails* Create(content::RenderFrame* render_frame);
   ~ThreatDOMDetails() override;
 
   // Begins extracting resource urls for the page currently loaded in
@@ skipping 13 matching lines @@
   void OnDestruct() override;
 
   void OnGetThreatDOMDetails();
 
   DISALLOW_COPY_AND_ASSIGN(ThreatDOMDetails);
 };
 
 }  // namespace safe_browsing
 
 #endif  // CHROME_RENDERER_SAFE_BROWSING_THREAT_DOM_DETAILS_H_