Added pinch viewport offset to history item.

public/web/WebView.h

Index: public/web/WebView.h
diff --git a/public/web/WebView.h b/public/web/WebView.h
index a5669eda463062f9281eff403cc2b0003c9ea76e..db90cd283c53e3d01733f5a0d101a8ae4e49b687 100644
--- a/public/web/WebView.h
+++ b/public/web/WebView.h
@@ -272,14 +272,6 @@ public:
     virtual float minimumPageScaleFactor() const = 0;
     virtual float maximumPageScaleFactor() const = 0;
 
-    // Save the WebView's current scroll and scale state. Each call to this function
-    // overwrites the previously saved scroll and scale state.
-    virtual void saveScrollAndScaleState() = 0;
-
-    // Restore the previously saved scroll and scale state. After restoring the
-    // state, this function deletes any saved scroll and scale state.
-    virtual void restoreScrollAndScaleState() = 0;
-
     // Reset any saved values for the scroll and scale state.
     virtual void resetScrollAndScaleState() = 0;