Move GetDocument method from WebFrame to WebLocalFrame.

chrome/renderer/safe_browsing/phishing_dom_feature_extractor.cc

 // 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.
 
 #include "chrome/renderer/safe_browsing/phishing_dom_feature_extractor.h"
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
 #include "base/containers/hash_tables.h"
 #include "base/location.h"
@@ skipping 372 matching lines @@
           cur_document_.Url(),
           net::registry_controlled_domains::EXCLUDE_PRIVATE_REGISTRIES);
 }
 
 blink::WebDocument PhishingDOMFeatureExtractor::GetNextDocument() {
   DCHECK(!cur_document_.IsNull());
   blink::WebFrame* frame = cur_document_.GetFrame();
   // Advance to the next frame that contains a document, with no wrapping.
   if (frame) {
     for (frame = frame->TraverseNext(); frame; frame = frame->TraverseNext()) {
-      if (!frame->GetDocument().IsNull()) {
-        return frame->GetDocument();
+      if (frame->IsWebLocalFrame() &&
+          !frame->ToWebLocalFrame()->GetDocument().IsNull()) {
+        return frame->ToWebLocalFrame()->GetDocument();

[Łukasz Anforowicz, 2017/06/15 20:15:59]

Skipping remote frames seems okay here?

[dcheng, 2017/06/15 23:17:00]

Yeah. That being said, I'm quite skeptical of the IsNull() check on WebDocument
here--this shouldn't really be a state that's visible to consumers of the Blink
public API, unless they're doing things at weird times.

You can add a TODO(dcheng): to play around with this.

[Łukasz Anforowicz, 2017/06/16 19:39:24]

Done.

       }
     }
   } else {
     // Keep track of how often frame traversal got "stuck" due to the
     // current subdocument getting removed from the frame tree.
     UMA_HISTOGRAM_COUNTS("SBClientPhishing.DOMFeatureFrameRemoved", 1);
   }
   return blink::WebDocument();
 }
 
@@ skipping 88 matching lines @@
   // Record number of script tags (discretized for numerical stability.)
   if (page_feature_state_->num_script_tags > 1) {
     features_->AddBooleanFeature(features::kPageNumScriptTagsGTOne);
     if (page_feature_state_->num_script_tags > 6) {
       features_->AddBooleanFeature(features::kPageNumScriptTagsGTSix);
     }
   }
 }
 
 }  // namespace safe_browsing