Deprecate step timing with position 'middle'

third_party/WebKit/Source/core/animation/AnimationInputHelpers.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 "core/animation/AnimationInputHelpers.h"
 
 #include "bindings/core/v8/ExceptionState.h"
 #include "core/SVGNames.h"
 #include "core/css/CSSValueList.h"
 #include "core/css/parser/CSSParser.h"
@@ skipping 236 matching lines @@
     }
     exception_state.ThrowTypeError("'" + string +
                                    "' is not a valid value for easing");
     return nullptr;
   }
   const CSSValueList* value_list = ToCSSValueList(value);
   if (value_list->length() > 1) {
     exception_state.ThrowTypeError("Easing may not be set to a list of values");
     return nullptr;
   }
-  return CSSToStyleMap::MapAnimationTimingFunction(value_list->Item(0), true);
+  return CSSToStyleMap::MapAnimationTimingFunction(value_list->Item(0), true,
+                                                   document);
 }
 
 }  // namespace blink