Implements CSSPropertyAPI for the font-size-adjust property.

A part of Project Ribbon, separating the parsing logic for CSS
properties from the parser into an API. This patch removes
CSSPropertyFontSizeAdjust from the switch statement in
parseSingleValue, and calls the API instead.

A function pointer to the parseSingleValue function from the API for the
page property is stored in a CSSPropertyDescriptor, and is called from
CSSPropertyParser.

This patch:
- Adds CSSPropertyAPIFontSizeAdjust.cpp to the BUILD.gn file.
- Adds api_class flag to CSSProperties.in, which indicates that
  CSSPropertyAPIFontSizeAdjust.h is generated.
- Moves the parsing logic for page from CSSPropertyParser.cpp to
  CSSPropertyAPIFontSizeAdjust.cpp, which implements
  CSSPropertyAPI.h.

BUG=668012

Review-Url: https://codereview.chromium.org/2617443005
Cr-Commit-Position: refs/heads/master@{#442814}

third_party/WebKit/Source/core/css/BUILD.gn

@@ -347,6 +347,7 @@ blink_core_sources("css") {
     "properties/CSSPropertyAPICaretColor.cpp",
     "properties/CSSPropertyAPIClip.cpp",
     "properties/CSSPropertyAPIColumnGap.cpp",
+    "properties/CSSPropertyAPIFontSizeAdjust.cpp",
     "properties/CSSPropertyAPISize.cpp",
     "properties/CSSPropertyAPITextDecorationColor.cpp",
     "properties/CSSPropertyAPITextDecorationSkip.cpp",

third_party/WebKit/Source/core/css/CSSProperties.in

@@ -166,7 +166,7 @@ direction inherited, custom_value, keyword_only, keywords=[ltr|rtl], initial_key
 font-family inherited, font, type_name=FontDescription::FamilyDescription, name_for_methods=FamilyDescription, converter=convertFontFamily
 font-kerning inherited, font, type_name=FontDescription::Kerning, name_for_methods=Kerning
 font-size interpolable, inherited, font, name_for_methods=Size, getter=getSize, converter=convertFontSize
-font-size-adjust runtime_flag=CSSFontSizeAdjust, interpolable, inherited, font, name_for_methods=SizeAdjust, converter=convertFontSizeAdjust
+font-size-adjust runtime_flag=CSSFontSizeAdjust, interpolable, inherited, font, name_for_methods=SizeAdjust, converter=convertFontSizeAdjust, api_class
 font-stretch inherited, font, type_name=FontStretch, name_for_methods=Stretch
 font-style inherited, font, type_name=FontStyle, name_for_methods=Style
 font-variant-ligatures inherited, font, type_name=VariantLigatures, name_for_methods=VariantLigatures, converter=convertFontVariantLigatures

third_party/WebKit/Source/core/css/parser/CSSPropertyParser.cpp

@@ -2588,12 +2588,6 @@ static CSSValue* consumeReflect(CSSParserTokenRange& range,
   return CSSReflectValue::create(direction, offset, mask);
 }
 
-static CSSValue* consumeFontSizeAdjust(CSSParserTokenRange& range) {
-  if (range.peek().id() == CSSValueNone)
-    return consumeIdent(range);
-  return consumeNumber(range, ValueRangeNonNegative);
-}
-
 static CSSValue* consumeImageOrientation(CSSParserTokenRange& range) {
   if (range.peek().id() == CSSValueFromImage)
     return consumeIdent(range);
@@ -3624,9 +3618,6 @@ const CSSValue* CSSPropertyParser::parseSingleValue(
       return consumeWebkitBorderImage(property, m_range, m_context);
     case CSSPropertyWebkitBoxReflect:
       return consumeReflect(m_range, m_context);
-    case CSSPropertyFontSizeAdjust:
-      ASSERT(RuntimeEnabledFeatures::cssFontSizeAdjustEnabled());
-      return consumeFontSizeAdjust(m_range);
     case CSSPropertyImageOrientation:
       ASSERT(RuntimeEnabledFeatures::imageOrientationEnabled());
       return consumeImageOrientation(m_range);

third_party/WebKit/Source/core/css/properties/CSSPropertyAPIFontSizeAdjust.cpp

+// Copyright 2017 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/css/properties/CSSPropertyAPIFontSizeAdjust.h"
+
+#include "core/css/parser/CSSPropertyParserHelpers.h"
+#include "platform/RuntimeEnabledFeatures.h"
+
+namespace blink {
+
+const CSSValue* CSSPropertyAPIFontSizeAdjust::parseSingleValue(
+    CSSParserTokenRange& range,
+    const CSSParserContext& context) {
+  DCHECK(RuntimeEnabledFeatures::cssFontSizeAdjustEnabled());
+  if (range.peek().id() == CSSValueNone)
+    return CSSPropertyParserHelpers::consumeIdent(range);
+  return CSSPropertyParserHelpers::consumeNumber(range, ValueRangeNonNegative);
+}
+
+}  // namespace blink