Added pinch viewport offset to history item.

Source/web/WebHistoryItem.cpp

Index: Source/web/WebHistoryItem.cpp
diff --git a/Source/web/WebHistoryItem.cpp b/Source/web/WebHistoryItem.cpp
index 66ac93fd633966aaac2a5a0ac0f0e63a68b4c392..ad68b65ecbcfe68a5d31fe17ed8b20f375a10898 100644
--- a/Source/web/WebHistoryItem.cpp
+++ b/Source/web/WebHistoryItem.cpp
@@ -35,6 +35,7 @@
 #include "core/loader/HistoryItem.h"
 #include "platform/network/FormData.h"
 #include "platform/weborigin/KURL.h"
+#include "public/platform/WebFloatPoint.h"
 #include "public/platform/WebHTTPBody.h"
 #include "public/platform/WebPoint.h"
 #include "public/platform/WebString.h"
@@ -96,6 +97,16 @@ void WebHistoryItem::setTarget(const WebString& target)
     m_private->setTarget(target);
 }
 
+WebFloatPoint WebHistoryItem::pinchViewportScrollOffset() const
+{
+    return m_private->pinchViewportScrollPoint();
+}
+
+void WebHistoryItem::setPinchViewportScrollOffset(const WebFloatPoint& scrollOffset)
+{
+    m_private->setPinchViewportScrollPoint(scrollOffset);
+}
+
 WebPoint WebHistoryItem::scrollOffset() const
 {
     return m_private->scrollPoint();