Add support for multiple text decorations with same line positioning

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

Index: third_party/WebKit/Source/core/css/resolver/StyleAdjuster.cpp
diff --git a/third_party/WebKit/Source/core/css/resolver/StyleAdjuster.cpp b/third_party/WebKit/Source/core/css/resolver/StyleAdjuster.cpp
index 87b4b97906a2c5031739e43b21a519270a0f2433..c28238baf16af6dde07041522ad99b91389678e6 100644
--- a/third_party/WebKit/Source/core/css/resolver/StyleAdjuster.cpp
+++ b/third_party/WebKit/Source/core/css/resolver/StyleAdjuster.cpp
@@ -111,7 +111,18 @@ static bool doesNotInheritTextDecoration(const ComputedStyle& style, const Eleme
 {
     return style.display() == INLINE_TABLE
         || style.display() == INLINE_BLOCK || style.display() == INLINE_BOX || isAtShadowBoundary(element)
-        || style.isFloating() || style.hasOutOfFlowPosition() || isOutermostSVGElement(element);
+        || style.isFloating() || style.hasOutOfFlowPosition() || isOutermostSVGElement(element)
+        || isHTMLRTElement(element);
+}
+
+// Certain elements (<a>, <font>) bind strongly to text decoration colors.

[Timothy Loh, 2015/10/12 00:11:16]

This sentence doesn't make sense to me.

[sashab, 2015/10/12 23:11:01]

I was trying to explain the weird behavior in a clever way. Turns out I was too
clever by half ;) Changed to say 'override', this probably makes more sense now
but isn't super informative. Suggestions welcome or if it's still not great I'll
keep thinking of a way to describe it.

+// "The font element is expected to override the color of any text decoration that
+// spans the text of the element to the used value of the element's 'color' property."
+// (from https://html.spec.whatwg.org/multipage/rendering.html#phrasing-content-3)
+// The <a> behavior is non-standard.
+static bool overridesTextDecorationColors(const Element* element)
+{
+    return element && (isHTMLFontElement(element) || isHTMLAnchorElement(element));
 }
 
 // FIXME: This helper is only needed because pseudoStyleForElement passes a null
@@ -204,8 +215,7 @@ void StyleAdjuster::adjustComputedStyle(ComputedStyle& style, const ComputedStyl
 
     if (doesNotInheritTextDecoration(style, element))
         style.clearAppliedTextDecorations();
-
-    style.applyTextDecorations();
+    style.applyTextDecorations(parentStyle.visitedDependentColor(CSSPropertyTextDecorationColor), overridesTextDecorationColors(element));
 
     if (style.overflowX() != OVISIBLE || style.overflowY() != OVISIBLE)
         adjustOverflow(style);