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

Source/core/dom/NodeRareData.h

Index: Source/core/dom/NodeRareData.h
diff --git a/Source/core/dom/NodeRareData.h b/Source/core/dom/NodeRareData.h
index f19088c088dc674027f483e475ac0af74691f79b..2f43c45bba6eb350bf430375e770d011dd3c581e 100644
--- a/Source/core/dom/NodeRareData.h
+++ b/Source/core/dom/NodeRareData.h
@@ -82,10 +82,7 @@ public:
     }
 
     unsigned connectedSubframeCount() const { return m_connectedFrameCount; }
-    void incrementConnectedSubframeCount(unsigned amount)
-    {
-        m_connectedFrameCount += amount;
-    }
+    void incrementConnectedSubframeCount(unsigned amount);
     void decrementConnectedSubframeCount(unsigned amount)
     {
         ASSERT(m_connectedFrameCount);