Oilpan: Schedule a precise GC when a page navigates

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 1009 matching lines @@
         m_didAccessInitialDocumentTimer.stop();
         didAccessInitialDocumentTimerFired(0);
     }
 }
 
 bool FrameLoader::prepareForCommit()
 {
     PluginScriptForbiddenScope forbidPluginDestructorScripting;
     RefPtrWillBeRawPtr<DocumentLoader> pdl = m_provisionalDocumentLoader;
 
+    if (m_frame->document()) {
+        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);
+    }
+
     if (m_documentLoader) {
         client()->dispatchWillClose();
         dispatchUnloadEvent();
     }
     m_frame->detachChildren();
     // The previous calls to dispatchUnloadEvent() and detachChildren() can
     // execute arbitrary script via things like unload events. If the executed
     // script intiates a new load or causes the current frame to be detached,
     // we need to abandon the current load.
     if (pdl != m_provisionalDocumentLoader)
@@ skipping 459 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