Remove obsolete pinch-zoom related code.

Source/web/WebViewImpl.h

Index: Source/web/WebViewImpl.h
diff --git a/Source/web/WebViewImpl.h b/Source/web/WebViewImpl.h
index af048f15e6bbc16e4e169954527d65d62b3b5da1..6e2b5baad9ed9347748258b22d36e6eb1bc2bb91 100644
--- a/Source/web/WebViewImpl.h
+++ b/Source/web/WebViewImpl.h
@@ -201,7 +201,6 @@ public:
     virtual void setDefaultPageScaleLimits(float minScale, float maxScale) override;
     virtual void setInitialPageScaleOverride(float) override;
     virtual void setMaximumLegibleScale(float) override;
-    virtual void setMainFrameScrollOffset(const WebPoint&) override;
     virtual void setPageScaleFactor(float) override;
     virtual void setPinchViewportOffset(const WebFloatPoint&) override;
     virtual WebFloatPoint pinchViewportOffset() const override;
@@ -279,6 +278,8 @@ public:
     void enableViewport();
     void disableViewport();
 
+    void setMainFrameScrollOffset(const WebPoint&);
+
     float defaultMinimumPageScaleFactor() const;
     float defaultMaximumPageScaleFactor() const;
     float minimumPageScaleFactor() const;