Split the CSSParserContext class out of CSSParserMode into its own file.

third_party/WebKit/Source/core/css/properties/CSSPropertyAPI.h

 // Copyright 2016 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.
 
 #ifndef CSSPropertyAPI_h
 #define CSSPropertyAPI_h
 
 #include "core/CSSPropertyNames.h"
 #include "core/css/CSSValue.h"
-#include "core/css/parser/CSSParserMode.h"
+#include "core/css/parser/CSSParserContext.h"
 #include "core/css/parser/CSSParserTokenRange.h"
 
 namespace blink {
 
 // We will use this API to represent all functions used for property-specific
 // logic inside the blink style engine. All specific properties are subclasses
 // of CSSPropertyAPI.
 //
 // To add a new property using this API:
 // - Make a class that implements CSSPropertyAPI, and implement the static
@@ skipping 13 matching lines @@
  public:
   // Parses a single CSS property and returns the corresponding CSSValue. If the
   // input is invalid it returns nullptr.
   static const CSSValue* parseSingleValue(CSSParserTokenRange&,
                                           const CSSParserContext&);
 };
 
 }  // namespace blink
 
 #endif  // CSSPropertyAPI_h