Trigger computation of font size when crossing foreignObject boundary

Source/core/css/resolver/StyleResolver.cpp

Index: Source/core/css/resolver/StyleResolver.cpp
diff --git a/Source/core/css/resolver/StyleResolver.cpp b/Source/core/css/resolver/StyleResolver.cpp
index 9878f21af0ef2732cc3142665bc8aa5f5714481d..0509d9612825f7d98b772e8934c3f44ef0ff060c 100644
--- a/Source/core/css/resolver/StyleResolver.cpp
+++ b/Source/core/css/resolver/StyleResolver.cpp
@@ -651,7 +651,7 @@ PassRefPtr<RenderStyle> StyleResolver::styleForElement(Element* element, RenderS
         }
     }
 
-    state.fontBuilder().initForStyleResolve(state.document(), state.style(), state.useSVGZoomRules());
+    state.fontBuilder().initForStyleResolve(state.document(), state.style());
 
     if (element->isLink()) {
         state.style()->setIsLink(true);
@@ -719,7 +719,7 @@ PassRefPtr<RenderStyle> StyleResolver::styleForKeyframe(Element* element, const
     state.setStyle(RenderStyle::clone(&elementStyle));
     state.setLineHeightValue(0);
 
-    state.fontBuilder().initForStyleResolve(state.document(), state.style(), state.useSVGZoomRules());
+    state.fontBuilder().initForStyleResolve(state.document(), state.style());
 
     // We don't need to bother with !important. Since there is only ever one
     // decl, there's nothing to override. So just add the first properties.
@@ -766,7 +766,7 @@ PassRefPtrWillBeRawPtr<AnimatableValue> StyleResolver::createAnimatableValueSnap
 {
     StyleResolverState state(element.document(), &element);
     state.setStyle(&style);
-    state.fontBuilder().initForStyleResolve(state.document(), state.style(), state.useSVGZoomRules());
+    state.fontBuilder().initForStyleResolve(state.document(), state.style());
     StyleBuilder::applyProperty(property, state, &value);
     return CSSAnimatableValueFactory::create(property, style);
 }
@@ -827,7 +827,7 @@ bool StyleResolver::pseudoStyleForElementInternal(Element& element, const Pseudo
         state.setParentStyle(RenderStyle::clone(state.style()));
     }
 
-    state.fontBuilder().initForStyleResolve(state.document(), state.style(), state.useSVGZoomRules());
+    state.fontBuilder().initForStyleResolve(state.document(), state.style());
 
     // Since we don't use pseudo-elements in any of our quirk/print
     // user agent rules, don't waste time walking those rules.
@@ -896,7 +896,7 @@ PassRefPtr<RenderStyle> StyleResolver::styleForPage(int pageIndex)
     ASSERT(rootElementStyle);
     state.style()->inheritFrom(rootElementStyle);
 
-    state.fontBuilder().initForStyleResolve(state.document(), state.style(), state.useSVGZoomRules());
+    state.fontBuilder().initForStyleResolve(state.document(), state.style());
 
     PageRuleCollector collector(rootElementStyle, pageIndex);
 
@@ -951,7 +951,7 @@ PassRefPtr<RenderStyle> StyleResolver::defaultStyleForElement()
 {
     StyleResolverState state(document(), 0);
     state.setStyle(RenderStyle::create());
-    state.fontBuilder().initForStyleResolve(document(), state.style(), state.useSVGZoomRules());
+    state.fontBuilder().initForStyleResolve(document(), state.style());
     state.style()->setLineHeight(RenderStyle::initialLineHeight());
     state.setLineHeightValue(0);
     state.fontBuilder().setInitial(state.style()->effectiveZoom());
@@ -1384,6 +1384,12 @@ void StyleResolver::applyMatchedProperties(StyleResolverState& state, const Matc
     applyMatchedProperties<HighPriorityProperties>(state, matchResult, true, matchResult.ranges.firstUserRule, matchResult.ranges.lastUserRule, applyInheritedOnly);
     applyMatchedProperties<HighPriorityProperties>(state, matchResult, true, matchResult.ranges.firstUARule, matchResult.ranges.lastUARule, applyInheritedOnly);
 
+    if (UNLIKELY(isSVGForeignObjectElement(element))) {
+        // RenderSVGRoot handles zooming for the whole SVG subtree, so foreignObject content should
+        // not be scaled again.
+        state.setEffectiveZoom(RenderStyle::initialZoom());
+    }

[rune, 2014/06/04 10:05:20]

If kept here, we need to document that it's important that it comes after
setting zoom which is one of the high priority properties applied above. Also,
that resetting the  effective zoom is really for the children, but it can be
done in the foreignObject since it's not used for anything, including font
computation, in svg elements.

Does that sound about right?

[davve, 2014/06/04 11:38:36]

Yes, that would work for me. Patch coming up.

[davve, 2014/06/04 13:27:20]

Added as a FIXME.

+
     if (cachedMatchedProperties && cachedMatchedProperties->renderStyle->effectiveZoom() != state.style()->effectiveZoom()) {
         state.fontBuilder().setFontDirty(true);
         applyInheritedOnly = false;
@@ -1460,7 +1466,7 @@ void StyleResolver::applyPropertiesToStyle(const CSSPropertyValue* properties, s
     StyleResolverState state(document(), document().documentElement(), style);
     state.setStyle(style);
 
-    state.fontBuilder().initForStyleResolve(document(), style, state.useSVGZoomRules());
+    state.fontBuilder().initForStyleResolve(document(), style);
 
     for (size_t i = 0; i < count; ++i) {
         if (properties[i].value) {