Fix selector namespace prefix resolution.

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

Index: third_party/WebKit/Source/core/css/StyleSheetContents.cpp
diff --git a/third_party/WebKit/Source/core/css/StyleSheetContents.cpp b/third_party/WebKit/Source/core/css/StyleSheetContents.cpp
index a29c1cc394709908380ffd419c1f4f54b27eca78..0ae663ebb06f8f16c9fa8b2e2456d5b97e0b34e2 100644
--- a/third_party/WebKit/Source/core/css/StyleSheetContents.cpp
+++ b/third_party/WebKit/Source/core/css/StyleSheetContents.cpp
@@ -313,14 +313,8 @@ void StyleSheetContents::parserAddNamespace(const AtomicString& prefix, const At
     result.storedValue->value = uri;
 }
 
-const AtomicString& StyleSheetContents::determineNamespace(const AtomicString& prefix)
-{
-    if (prefix.isNull())
-        return defaultNamespace();
-    if (prefix.isEmpty())
-        return emptyAtom; // No namespace. If an element/attribute has a namespace, we won't match it.
-    if (prefix == starAtom)
-        return starAtom; // We'll match any namespace.
+const AtomicString& StyleSheetContents::namespaceURIFromPrefix(const AtomicString& prefix)
+{
     return m_namespaces.get(prefix);
 }