CSS Properties and Values API: Implement computation / computational independence

third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp

Index: third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp
diff --git a/third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp b/third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp
index 6554f5908b571b2cadb0c52663a6502f429ae6a0..a6d75282047171e98676bf81232c4a4fed737f7b 100644
--- a/third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp
+++ b/third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp
@@ -1103,7 +1103,21 @@ PassRefPtr<StylePath> StyleBuilderConverter::convertPathOrNone(StyleResolverStat
 
 const CSSValue& StyleBuilderConverter::convertRegisteredPropertyValue(const StyleResolverState& state, const CSSValue& value)
 {
-    // TODO(timloh): Resolve ems, etc.
+    // TODO(timloh): Images and transform-function values can also contain lengths.
+    if (value.isValueList()) {
+        CSSValueList* newList = CSSValueList::createSpaceSeparated();
+        for (const CSSValue* innerValue : toCSSValueList(value))
+            newList->append(convertRegisteredPropertyValue(state, *innerValue));
+        return *newList;
+    }
+
+    if (value.isPrimitiveValue()) {
+        const CSSPrimitiveValue& primitiveValue = toCSSPrimitiveValue(value);
+        if (primitiveValue.isCalculated() || CSSPrimitiveValue::isRelativeUnit(primitiveValue.typeWithCalcResolved())) {
+            Length length = primitiveValue.convertToLength(state.cssToLengthConversionData().copyWithAdjustedZoom(1));

[sashab, 2016/09/19 23:25:03]

Why not use state.style.zoom()?

[alancutter (OOO until 2018), 2016/09/20 00:15:55]

Or avoid the copy and just use style.effectiveZoom() when creating the
CSSPrimitiveValue below.

[Timothy Loh, 2016/09/21 01:12:04]

I figured it'd be nicer to not have any chance of values changing slightly due
to rounding at different zoom levels. I'm not sure if it really makes a
difference, lmk what you think.

+            return *CSSPrimitiveValue::create(length, 1);
+        }
+    }

[alancutter (OOO until 2018), 2016/09/20 00:39:44]

Do we have tests for this code?

[Timothy Loh, 2016/09/21 01:12:05]

Uhh... I'll go add some :)

     return value;
 }