matchMedia('(display-mode: <notValid>)').matches should not evaluate true

third_party/WebKit/Source/core/css/MediaQueryEvaluator.cpp

 /*
  * CSS Media Query Evaluator
  *
  * Copyright (C) 2006 Kimmo Kinnunen <kimmo.t.kinnunen@nokia.com>.
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Intel Corporation. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ skipping 203 matching lines @@
             return numberValue(value, number) && compareValue(0, static_cast<int>(number), op);
         }
         return false;
     }
 
     return colorMediaFeatureEval(value, op, mediaValues);
 }
 
 static bool displayModeMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
 {
+    // isValid() is false if there is no parameter. Without parameter we should return true to indicate that
+    // displayModeMediaFeature is enabled in the browser.
+    if (!value.isValid())
+        return true;
+
     if (!value.isID)
-        return true;
+        return false;
 
     WebDisplayMode mode = mediaValues.displayMode();
     switch (value.id) {
     case CSSValueFullscreen:
         return mode == WebDisplayModeFullscreen;
     case CSSValueStandalone:
         return mode == WebDisplayModeStandalone;
     case CSSValueMinimalUi:
         return mode == WebDisplayModeMinimalUi;
     case CSSValueBrowser:
@@ skipping 418 matching lines @@
     // Call the media feature evaluation function. Assume no prefix and let
     // trampoline functions override the prefix if prefix is used.
     EvalFunc func = gFunctionMap->get(expr->mediaFeature().impl());
     if (func)
         return func(expr->expValue(), NoPrefix, *m_mediaValues);
 
     return false;
 }
 
 } // namespace