Fix the logic that limits the number of frames in a page.

Source/core/dom/NodeRareData.cpp

Index: Source/core/dom/NodeRareData.cpp
diff --git a/Source/core/dom/NodeRareData.cpp b/Source/core/dom/NodeRareData.cpp
index 65d14a36a2cba288104afc7dbc6b184b378807f3..6365a9caeeb5e5c3bf061559c178fecba0ab24ae 100644
--- a/Source/core/dom/NodeRareData.cpp
+++ b/Source/core/dom/NodeRareData.cpp
@@ -73,6 +73,12 @@ void NodeRareData::finalizeGarbageCollectedObject()
         this->~NodeRareData();
 }
 
+void NodeRareData::incrementConnectedSubframeCount(unsigned amount)
+{
+    RELEASE_ASSERT_WITH_SECURITY_IMPLICATION((m_connectedFrameCount + amount) <= FrameHost::maxNumberOfFrames);
+    m_connectedFrameCount += amount;
+}
+
 // Ensure the 10 bits reserved for the m_connectedFrameCount cannot overflow
 static_assert(FrameHost::maxNumberOfFrames < (1 << NodeRareData::ConnectedFrameCountBits), "Frame limit should fit in rare data count");