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

Source/core/css/MediaValues.cpp

Index: Source/core/css/MediaValues.cpp
diff --git a/Source/core/css/MediaValues.cpp b/Source/core/css/MediaValues.cpp
index 2776089bf747ab02695d003aa18c7beb7956bdcc..1a305239f26e6cc5b48767948d7716a606f8f6db 100644
--- a/Source/core/css/MediaValues.cpp
+++ b/Source/core/css/MediaValues.cpp
@@ -105,15 +105,18 @@ const String MediaValues::calculateMediaType(LocalFrame* frame) const
     return frame->view()->mediaType();
 }
 
-DisplayMode MediaValues::calculateDisplayMode(LocalFrame* frame) const
+WebDisplayMode MediaValues::calculateDisplayMode(LocalFrame* frame) const
 {
     ASSERT(frame);
-    DisplayMode mode = frame->host()->settings().displayModeOverride();
+    WebDisplayMode mode = frame->host()->settings().displayModeOverride();
 
-    if (mode != DisplayModeUndefined)
+    if (mode != WebDisplayModeUndefined)
         return mode;
 
-    return DisplayModeBrowser;
+    if (!frame->view())
+        return WebDisplayModeBrowser;
+
+    return frame->view()->displayMode();
 }
 
 bool MediaValues::calculateThreeDEnabled(LocalFrame* frame) const