Turn ViewportAnchors into stack allocated objects.

Source/web/ResizeViewportAnchor.h

Index: Source/web/ResizeViewportAnchor.h
diff --git a/Source/web/ResizeViewportAnchor.h b/Source/web/ResizeViewportAnchor.h
index 40652326741c37fe6d9de78b53970605352666fd..0e4bab0c95b1e18faee4c2199855c431fdaec8c2 100644
--- a/Source/web/ResizeViewportAnchor.h
+++ b/Source/web/ResizeViewportAnchor.h
@@ -18,12 +18,10 @@ class PinchViewport;
 // restores to that scroll offset so that document location appears exactly
 // unchanged to the user.
 class ResizeViewportAnchor : public ViewportAnchor {
+    STACK_ALLOCATED();
 public:
     ResizeViewportAnchor(FrameView& rootFrameView, PinchViewport&);
-    virtual ~ResizeViewportAnchor() { }
-
-    virtual void setAnchor();
-    virtual void restoreToAnchor();
+    ~ResizeViewportAnchor();
 
 private:
     // Inner viewport origin in the reference frame of the root document, in CSS
@@ -33,4 +31,4 @@ private:
 
 } // namespace blink
 
-#endif
+#endif // ResizeViewportAnchor_h