Remove old pinch-zoom paths from Blink

public/web/WebView.h

Index: public/web/WebView.h
diff --git a/public/web/WebView.h b/public/web/WebView.h
index 20aeff9df75416bb5bf5ed6cfa2cdffcb1222333..50382cf5fac77b314f6b9f6d30b4f99426c02072 100644
--- a/public/web/WebView.h
+++ b/public/web/WebView.h
@@ -231,7 +231,7 @@ public:
     // Scales a page by a factor of scaleFactor and then sets a scroll position to (x, y).
     // setPageScaleFactor() magnifies and shrinks a page without affecting layout.
     // On the other hand, zooming affects layout of the page.
-    virtual void setPageScaleFactor(float scaleFactor, const WebPoint& origin) = 0;
+    virtual void setPageScaleFactor(float scaleFactor, const WebPoint& origin) { setPageScaleFactor(scaleFactor); }
 
     // TODO: Reevaluate if this is needed once all users are converted to using the
     // virtual viewport pinch model.