Make it possible to set the display mode from the WebView API

Source/web/WebViewImpl.cpp

Index: Source/web/WebViewImpl.cpp
diff --git a/Source/web/WebViewImpl.cpp b/Source/web/WebViewImpl.cpp
index 2e1ad22b19633d99bfdc6c0ecb6bc4a3e7812ebd..d22ab3e55dda011c4fd696636379bc9a374d27c4 100644
--- a/Source/web/WebViewImpl.cpp
+++ b/Source/web/WebViewImpl.cpp
@@ -544,6 +544,14 @@ void WebViewImpl::handleMouseDown(LocalFrame& mainFrame, const WebMouseEvent& ev
     }
 }
 
+void WebViewImpl::setDisplayMode(WebDisplayMode mode)
+{
+    if (!mainFrameImpl() || !mainFrameImpl()->frameView())
+        return;
+
+    mainFrameImpl()->frameView()->setDisplayMode(mode);
+}
+
 void WebViewImpl::mouseContextMenu(const WebMouseEvent& event)
 {
     if (!mainFrameImpl() || !mainFrameImpl()->frameView())