Update css styles after modifying display mode

Source/core/frame/FrameView.cpp

Index: Source/core/frame/FrameView.cpp
diff --git a/Source/core/frame/FrameView.cpp b/Source/core/frame/FrameView.cpp
index c9c429ac81677e8f703528ccb03a89e71f526610..e9c8e97c1ab6a3f8f46ad0f8faf1a9d4a1dcb0ff 100644
--- a/Source/core/frame/FrameView.cpp
+++ b/Source/core/frame/FrameView.cpp
@@ -780,7 +780,6 @@ void FrameView::performPreLayoutTasks()
 
     // Viewport-dependent media queries may cause us to need completely different style information.
     if (!document->styleResolver() || (wasResized && document->styleResolver()->mediaQueryAffectedByViewportChange())) {
-        document->styleResolverChanged();
         document->mediaQueryAffectingValueChanged();
     } else if (wasResized) {
         document->evaluateMediaQueryList();
@@ -1178,7 +1177,11 @@ void FrameView::addPartToUpdate(LayoutEmbeddedObject& object)
 
 void FrameView::setDisplayMode(WebDisplayMode mode)
 {
+    if (mode == m_displayMode)
+        return;
+
     m_displayMode = mode;
+
     if (m_frame->document())
         m_frame->document()->mediaQueryAffectingValueChanged();
 }