Add support for 'display-mode' MQ defined in Manifest spec

Source/core/css/MediaValues.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/css/MediaValues.h"
 
 #include "core/css/CSSHelper.h"
 #include "core/css/MediaValuesCached.h"
 #include "core/css/MediaValuesDynamic.h"
@@ skipping 87 matching lines @@
 }
 
 const String MediaValues::calculateMediaType(LocalFrame* frame) const
 {
     ASSERT(frame);
     if (!frame->view())
         return emptyAtom;
     return frame->view()->mediaType();
 }
 
+DisplayMode MediaValues::calculateDisplayMode(LocalFrame* frame) const
+{
+    ASSERT(frame);
+    DisplayMode mode = frame->host()->settings().displayModeOverride();
+
+    if (mode != DisplayModeUndefined)
+        return mode;
+
+    return DisplayModeBrowser;
+}
+
 bool MediaValues::calculateThreeDEnabled(LocalFrame* frame) const
 {
     ASSERT(frame && frame->contentRenderer() && frame->contentRenderer()->compositor());
     bool threeDEnabled = false;
     if (RenderView* view = frame->contentRenderer())
         threeDEnabled = view->compositor()->hasAcceleratedCompositing();
     return threeDEnabled;
 }
 
 PointerType MediaValues::calculatePrimaryPointerType(LocalFrame* frame) const
@@ skipping 84 matching lines @@
 }
 
 LocalFrame* MediaValues::frameFrom(Document& document)
 {
     Document* executingDocument = document.importsController() ? document.importsController()->master() : &document;
     ASSERT(executingDocument);
     return executingDocument->frame();
 }
 
 } // namespace