Fix and adjust PageNavigationGC threshold

third_party/WebKit/Source/core/loader/FrameLoader.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2008 Alp Toker <alp@atoker.com>
  * Copyright (C) Research In Motion Limited 2009. All rights reserved.
  * Copyright (C) 2011 Kris Jordan <krisjordan@gmail.com>
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ skipping 1026 matching lines @@
         didAccessInitialDocumentTimerFired(0);
     }
 }
 
 bool FrameLoader::prepareForCommit()
 {
     PluginScriptForbiddenScope forbidPluginDestructorScripting;
     RefPtrWillBeRawPtr<DocumentLoader> pdl = m_provisionalDocumentLoader;
 
     if (m_frame->document()) {
+        unsigned nodeCount = 0;
+        for (Frame* frame = m_frame; frame; frame = frame->tree().traverseNext()) {
+            if (frame->isLocalFrame()) {
+                LocalFrame* localFrame = toLocalFrame(frame);
+                nodeCount += localFrame->document()->nodeCount();
+            }
+        }
         unsigned totalNodeCount = InstanceCounters::counterValue(InstanceCounters::NodeCounter);
-        int nodeCount = static_cast<int>(totalNodeCount);
-        for (Document* document : Document::liveDocumentSet()) {
-            if (document != m_frame->document())
-                nodeCount -= document->nodeCount();
-        }
-        ASSERT(nodeCount >= 0);
         float ratio = static_cast<float>(nodeCount) / totalNodeCount;
         ThreadState::current()->schedulePageNavigationGCIfNeeded(ratio);
     }
 
     // Don't allow any new child frames to load in this frame: attaching a new
     // child frame during or after detaching children results in an attached
     // frame on a detached DOM tree, which is bad.
     SubframeLoadingDisabler disabler(m_frame->document());
     if (m_documentLoader) {
         client()->dispatchWillClose();
@@ skipping 508 matching lines @@
     // FIXME: We need a way to propagate insecure requests policy flags to
     // out-of-process frames. For now, we'll always use default behavior.
     if (!parentFrame->isLocalFrame())
         return nullptr;
 
     ASSERT(toLocalFrame(parentFrame)->document());
     return toLocalFrame(parentFrame)->document()->insecureNavigationsToUpgrade();
 }
 
 } // namespace blink