Use an MutationObserver to check when a password form disappears after XHR

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
@@ skipping 62 matching lines @@
 #include "core/dom/DocumentFragment.h"
 #include "core/dom/DocumentParserTiming.h"
 #include "core/dom/DocumentType.h"
 #include "core/dom/Element.h"
 #include "core/dom/ElementCreationOptions.h"
 #include "core/dom/ElementDataCache.h"
 #include "core/dom/ElementRegistrationOptions.h"
 #include "core/dom/ElementTraversal.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/dom/ExecutionContextTask.h"
+#include "core/dom/FormElementObserver.h"
 #include "core/dom/FrameRequestCallback.h"
 #include "core/dom/IntersectionObserverController.h"
 #include "core/dom/LayoutTreeBuilderTraversal.h"
 #include "core/dom/LiveNodeList.h"
 #include "core/dom/MutationObserver.h"
 #include "core/dom/NodeChildRemovalTracker.h"
 #include "core/dom/NodeComputedStyle.h"
 #include "core/dom/NodeFilter.h"
 #include "core/dom/NodeIterator.h"
 #include "core/dom/NodeRareData.h"
@@ skipping 6640 matching lines @@
   visitor->Trace(svg_extensions_);
   visitor->Trace(timeline_);
   visitor->Trace(compositor_pending_animations_);
   visitor->Trace(context_document_);
   visitor->Trace(canvas_font_cache_);
   visitor->Trace(intersection_observer_controller_);
   visitor->Trace(snap_coordinator_);
   visitor->Trace(resize_observer_controller_);
   visitor->Trace(property_registry_);
   visitor->Trace(network_state_observer_);
+  visitor->Trace(form_element_observer_);
   Supplementable<Document>::Trace(visitor);
   TreeScope::Trace(visitor);
   ContainerNode::Trace(visitor);
   ExecutionContext::Trace(visitor);
   SecurityContext::Trace(visitor);
   SynchronousMutationNotifier::Trace(visitor);
 }
 
 void Document::RecordDeferredLoadReason(WouldLoadReason reason) {
   DCHECK(would_load_reason_ == WouldLoadReason::kInvalid ||
          reason != WouldLoadReason::kCreated);
   DCHECK(reason != WouldLoadReason::kInvalid);
   DCHECK(GetFrame());
   DCHECK(GetFrame()->IsCrossOriginSubframe());
   if (reason <= would_load_reason_ ||
       !GetFrame()->Loader().StateMachine()->CommittedFirstRealDocumentLoad())
     return;
   for (int i = static_cast<int>(would_load_reason_) + 1;
        i <= static_cast<int>(reason); ++i)
     RecordLoadReasonToHistogram(static_cast<WouldLoadReason>(i));
   would_load_reason_ = reason;
 }
 
+FormElementObserver* Document::GetFormElementObserver() {
+  if (!form_element_observer_)
+    form_element_observer_ = new FormElementObserver(*this);
+  return form_element_observer_;
+}
+
 DEFINE_TRACE_WRAPPERS(Document) {
   // node_lists_ are traced in their corresponding NodeListsNodeData, keeping
   // them only alive for live nodes. Otherwise we would keep lists of dead
   // nodes alive that have not yet been invalidated.
   visitor->TraceWrappers(imports_controller_);
   visitor->TraceWrappers(implementation_);
   visitor->TraceWrappers(style_sheet_list_);
   visitor->TraceWrappers(style_engine_);
   // Cannot trace in Supplementable<Document> as it is part of platform/ and
   // thus cannot refer to ScriptWrappableVisitor.
@@ skipping 14 matching lines @@
 }
 
 void showLiveDocumentInstances() {
   WeakDocumentSet& set = liveDocumentSet();
   fprintf(stderr, "There are %u documents currently alive:\n", set.size());
   for (blink::Document* document : set)
     fprintf(stderr, "- Document %p URL: %s\n", document,
             document->Url().GetString().Utf8().data());
 }
 #endif