Parse ranges for stretch in @font-face

Allow ranges for font-stretch in @font-face, compare
https://drafts.csswg.org/css-fonts-4/#font-prop-desc

Bug: 749091
Change-Id: I79cafc1f7c496617bfb4eca21e28b4b451bdfae5
Reviewed-on: https://chromium-review.googlesource.com/582862
Commit-Queue: Dominik Röttsches <drott@chromium.org>
Reviewed-by: meade_UTC10 <meade@chromium.org>
Reviewed-by: Bugs Nash <bugsnash@chromium.org>
Cr-Commit-Position: refs/heads/master@{#491697}

third_party/WebKit/LayoutTests/external/wpt/css-fonts/variations/font-parse-numeric-stretch-style-weight.html

@@ -25,8 +25,8 @@ var styleValidTests = {
 };
 
 var styleInvalidTests = {
-  'weight': ['100 400'],
-  'stretch': ['100% 110%', '0%', '100% 150%']
+  'weight': ['100 400', 'calc(0 - 100)', 'calc(200 + 801)'],
+  'stretch': ['100% 110%', '0%', '100% 150%', 'calc(1 + 10%)']
 };
 
 function testParseStyle() {
@@ -64,6 +64,9 @@ var faceTests = {
     ['100%', '100%'],
     ['110%', '110%'],
     ['111.5%', '111.5%'],
+    [ "50% 200%", "50% 200%" ],
+    [ "0.1% 1%", "0.1% 1%" ],
+    [ "900% 901%", "900% 901%" ],
     ['ultra-condensed', 'ultra-condensed'],
     ['ultra-expanded', 'ultra-expanded'],
   ],
@@ -82,8 +85,8 @@ var faceInvalidTests = {
     'a b c',
   ],
   'stretch': [
-    '0%', '60% 70% 80%', 'a%', 'a b c', '0.1', '-60% 80%', 'ultra-expannnned',
-    '50% 0'
+    '-0.5%', '-1%', '0%', 'calc(0% - 10%)', '60% 70% 80%', 'a%', 'a b c', '0.1',
+    '-60% 80%', 'ultra-expannnned', '50% 0'
   ],
 };
 

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

@@ -813,7 +813,8 @@ bool CSSPropertyParser::ParseFontFaceDescriptor(CSSPropertyID prop_id) {
       parsed_value = ConsumeFontDisplay(range_);
       break;
     case CSSPropertyFontStretch:
-      parsed_value = CSSPropertyFontUtils::ConsumeFontStretch(range_);
+      parsed_value = CSSPropertyFontUtils::ConsumeFontStretch(
+          range_, kCSSFontFaceRuleMode);
       break;
     case CSSPropertyFontStyle:
       parsed_value = CSSPropertyFontUtils::ConsumeFontStyle(range_);

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

@@ -4,15 +4,16 @@
 
 #include "core/css/properties/CSSPropertyAPIFontStretch.h"
 
+#include "core/css/parser/CSSParserContext.h"
 #include "core/css/properties/CSSPropertyFontUtils.h"
 
 namespace blink {
 
 const CSSValue* CSSPropertyAPIFontStretch::parseSingleValue(
     CSSParserTokenRange& range,
-    const CSSParserContext&,
+    const CSSParserContext& context,
     const CSSParserLocalContext&) {
-  return CSSPropertyFontUtils::ConsumeFontStretch(range);
+  return CSSPropertyFontUtils::ConsumeFontStretch(range, context.Mode());
 }
 
 }  // namespace blink

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

@@ -126,15 +126,28 @@ static CSSValue* CombineToRangeListOrNull(const CSSPrimitiveValue* range_start,
   return value_list;
 }
 
-CSSValue* CSSPropertyFontUtils::ConsumeFontStretch(CSSParserTokenRange& range) {
+CSSValue* CSSPropertyFontUtils::ConsumeFontStretch(
+    CSSParserTokenRange& range,
+    const CSSParserMode& parser_mode) {
   CSSIdentifierValue* parsed_keyword = ConsumeFontStretchKeywordOnly(range);
   if (parsed_keyword)
     return parsed_keyword;
-  CSSPrimitiveValue* percent =
+
+  CSSPrimitiveValue* start_percent =
+      CSSPropertyParserHelpers::ConsumePercent(range, kValueRangeNonNegative);
+  if (!start_percent || start_percent->GetFloatValue() <= 0)
+    return nullptr;
+
+  // In a non-font-face context, more than one percentage is not allowed.
+  if (parser_mode != kCSSFontFaceRuleMode || range.AtEnd())
+    return start_percent;
+
+  CSSPrimitiveValue* end_percent =
       CSSPropertyParserHelpers::ConsumePercent(range, kValueRangeNonNegative);
-  if (!percent || percent->GetFloatValue() <= 0)
+  if (!end_percent || end_percent->GetFloatValue() <= 0)
     return nullptr;
-  return percent;
+
+  return CombineToRangeListOrNull(start_percent, end_percent);
 }
 
 CSSValue* CSSPropertyFontUtils::ConsumeFontWeight(

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

@@ -35,7 +35,8 @@ class CSSPropertyFontUtils {
 
   static CSSIdentifierValue* ConsumeFontStretchKeywordOnly(
       CSSParserTokenRange&);
-  static CSSValue* ConsumeFontStretch(CSSParserTokenRange&);
+  static CSSValue* ConsumeFontStretch(CSSParserTokenRange&,
+                                      const CSSParserMode&);
   static CSSValue* ConsumeFontStyle(CSSParserTokenRange&);
   static CSSValue* ConsumeFontWeight(CSSParserTokenRange&,
                                      const CSSParserMode&);