Delete unused WebViewBenchmarkSupport interface

Source/web/WebViewImpl.cpp

Index: Source/web/WebViewImpl.cpp
diff --git a/Source/web/WebViewImpl.cpp b/Source/web/WebViewImpl.cpp
index 0fc79df8a17a0925508dfff0ed5945cd5d88150c..716f0667fb2d25203ba30c4a21d6e05aecd07cc8 100644
--- a/Source/web/WebViewImpl.cpp
+++ b/Source/web/WebViewImpl.cpp
@@ -405,7 +405,6 @@ WebViewImpl::WebViewImpl(WebViewClient* client)
     , m_autofillPopup(0)
     , m_isTransparent(false)
     , m_tabsToLinks(false)
-    , m_benchmarkSupport(this)
     , m_layerTreeView(0)
     , m_rootLayer(0)
     , m_rootGraphicsLayer(0)
@@ -848,11 +847,6 @@ void WebViewImpl::enableFakePageScaleAnimationForTesting(bool enable)
     m_enableFakePageScaleAnimationForTesting = enable;
 }
 
-WebViewBenchmarkSupport* WebViewImpl::benchmarkSupport()
-{
-    return &m_benchmarkSupport;
-}
-
 void WebViewImpl::setShowFPSCounter(bool show)
 {
     if (m_layerTreeView) {