[selectors4] Implement :focus-within pseudo-class

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

Index: third_party/WebKit/Source/core/css/CSSSelector.cpp
diff --git a/third_party/WebKit/Source/core/css/CSSSelector.cpp b/third_party/WebKit/Source/core/css/CSSSelector.cpp
index 7fa6c20bd0c3accdd19a18b455057f8bbd3dd4e7..67a8600cc125776b819f34f54375b3712884ed9d 100644
--- a/third_party/WebKit/Source/core/css/CSSSelector.cpp
+++ b/third_party/WebKit/Source/core/css/CSSSelector.cpp
@@ -216,6 +216,7 @@ PseudoId CSSSelector::GetPseudoId(PseudoType type) {
     case kPseudoHover:
     case kPseudoDrag:
     case kPseudoFocus:
+    case kPseudoFocusWithin:
     case kPseudoActive:
     case kPseudoChecked:
     case kPseudoEnabled:
@@ -333,6 +334,7 @@ const static NameToPseudoStruct kPseudoTypeWithoutArgumentsMap[] = {
     {"first-line", CSSSelector::kPseudoFirstLine},
     {"first-of-type", CSSSelector::kPseudoFirstOfType},
     {"focus", CSSSelector::kPseudoFocus},
+    {"focus-within", CSSSelector::kPseudoFocusWithin},
     {"future", CSSSelector::kPseudoFutureCue},
     {"horizontal", CSSSelector::kPseudoHorizontal},
     {"host", CSSSelector::kPseudoHost},
@@ -548,6 +550,7 @@ void CSSSelector::UpdatePseudoType(const AtomicString& value,
     case kPseudoFirstChild:
     case kPseudoFirstOfType:
     case kPseudoFocus:
+    case kPseudoFocusWithin:
     case kPseudoFullPageMedia:
     case kPseudoFullScreen:
     case kPseudoFullScreenAncestor: