CSS Properties & Values API: Support <resolution> values

This patch adds support for <resolution>-typed registered properties.
We already parse the string '<resolution>', so this patch just adds the
logic to parse the actual <resolution> values.

BUG=641877

Review-Url: https://codereview.chromium.org/2618553003
Cr-Commit-Position: refs/heads/master@{#441795}

third_party/WebKit/LayoutTests/custom-properties/register-property-syntax-parsing-expected.txt

@@ -34,8 +34,9 @@ PASS syntax:'<angle>', initialValue:'20.5rad' is valid
 PASS syntax:'<angle>', initialValue:'calc(50grad + 3.14159rad)' is valid 
 PASS syntax:'<time>', initialValue:'2s' is valid 
 PASS syntax:'<time>', initialValue:'calc(2s - 9ms)' is valid 
-FAIL syntax:'<resolution>', initialValue:'10dpi' is valid Failed to execute 'registerProperty' on 'CSS': The initial value provided does not parse for the given syntax.
-FAIL syntax:'<resolution>', initialValue:'-5.3dpcm' is valid Failed to execute 'registerProperty' on 'CSS': The initial value provided does not parse for the given syntax.
+PASS syntax:'<resolution>', initialValue:'10dpi' is valid 
+PASS syntax:'<resolution>', initialValue:'3dPpX' is valid 
+PASS syntax:'<resolution>', initialValue:'-5.3dpcm' is valid 
 FAIL syntax:'<transform-function>', initialValue:'scale(2)' is valid Failed to execute 'registerProperty' on 'CSS': The initial value provided does not parse for the given syntax.
 FAIL syntax:'<transform-function>+', initialValue:'translateX(2px) rotate(20deg)' is valid Failed to execute 'registerProperty' on 'CSS': The initial value provided does not parse for the given syntax.
 PASS syntax:'<color>', initialValue:'rgb(12, 34, 56)' is valid 

third_party/WebKit/LayoutTests/custom-properties/register-property-syntax-parsing.html

@@ -60,6 +60,7 @@ assert_valid("<angle>", "calc(50grad + 3.14159rad)");
 assert_valid("<time>", "2s");
 assert_valid("<time>", "calc(2s - 9ms)");
 assert_valid("<resolution>", "10dpi");
+assert_valid("<resolution>", "3dPpX");
 assert_valid("<resolution>", "-5.3dpcm");
 assert_valid("<transform-function>", "scale(2)");
 assert_valid("<transform-function>+", "translateX(2px) rotate(20deg)");

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

@@ -165,7 +165,7 @@ const CSSValue* consumeSingleType(const CSSSyntaxComponent& syntax,
     case CSSSyntaxType::Time:
       return consumeTime(range, ValueRange::ValueRangeAll);
     case CSSSyntaxType::Resolution:
-      return nullptr;  // TODO(timloh): Implement this.
+      return consumeResolution(range);
     case CSSSyntaxType::TransformFunction:
       return nullptr;  // TODO(timloh): Implement this.
     case CSSSyntaxType::CustomIdent:

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

@@ -313,6 +313,21 @@ CSSPrimitiveValue* consumeTime(CSSParserTokenRange& range,
   return nullptr;
 }
 
+CSSPrimitiveValue* consumeResolution(CSSParserTokenRange& range) {
+  const CSSParserToken& token = range.peek();
+  // Unlike the other types, calc() does not work with <resolution>.
+  if (token.type() != DimensionToken)
+    return nullptr;
+  CSSPrimitiveValue::UnitType unit = token.unitType();
+  if (unit == CSSPrimitiveValue::UnitType::DotsPerPixel ||
+      unit == CSSPrimitiveValue::UnitType::DotsPerInch ||
+      unit == CSSPrimitiveValue::UnitType::DotsPerCentimeter) {
+    return CSSPrimitiveValue::create(
+        range.consumeIncludingWhitespace().numericValue(), unit);
+  }
+  return nullptr;
+}
+
 CSSIdentifierValue* consumeIdent(CSSParserTokenRange& range) {
   if (range.peek().type() != IdentToken)
     return nullptr;

third_party/WebKit/Source/core/css/parser/CSSPropertyParserHelpers.h

@@ -52,6 +52,7 @@ CSSPrimitiveValue* consumeLengthOrPercent(
     UnitlessQuirk = UnitlessQuirk::Forbid);
 CSSPrimitiveValue* consumeAngle(CSSParserTokenRange&);
 CSSPrimitiveValue* consumeTime(CSSParserTokenRange&, ValueRange);
+CSSPrimitiveValue* consumeResolution(CSSParserTokenRange&);
 
 CSSIdentifierValue* consumeIdent(CSSParserTokenRange&);
 CSSIdentifierValue* consumeIdentRange(CSSParserTokenRange&,