Oilpan: Schedule a precise GC when a page navigates

Source/core/dom/Document.cpp

Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index 8668dd20dee17af73c1de393abae62a90f05e65d..daab4c30c1f126968f794b2d53384363bccc905c 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -601,6 +601,16 @@ void Document::dispose()
 }
 #endif
 
+unsigned Document::nodeCount() const
+{
+    unsigned count = 0;
+    for (Node& node : NodeTraversal::inclusiveDescendantsOf(*this)) {
+        ASSERT_UNUSED(node, &node);
+        count++;
+    }
+    return count;
+}
+
 SelectorQueryCache& Document::selectorQueryCache()
 {
     if (!m_selectorQueryCache)