Don't match empty style rules.

Source/core/css/ElementRuleCollector.cpp

Index: Source/core/css/ElementRuleCollector.cpp
diff --git a/Source/core/css/ElementRuleCollector.cpp b/Source/core/css/ElementRuleCollector.cpp
index ed245341ee8f55b0216a8778fc6ba3333af4da53..5fa2a5f9280f1f3511728f9877581edc84c406a3 100644
--- a/Source/core/css/ElementRuleCollector.cpp
+++ b/Source/core/css/ElementRuleCollector.cpp
@@ -280,12 +280,14 @@ void ElementRuleCollector::collectRuleIfMatches(const RuleData& ruleData, Cascad
         return;
 
     StyleRule* rule = ruleData.rule();
+
+    // If the rule has no properties to apply, then ignore it in the non-debug mode.
+    const StylePropertySet& properties = rule->properties();
+    if (properties.isEmpty() && !matchRequest.includeEmptyRules)
+        return;
+
     SelectorChecker::MatchResult result;
     if (ruleMatches(ruleData, matchRequest.scope, &result)) {
-        // If the rule has no properties to apply, then ignore it in the non-debug mode.
-        const StylePropertySet& properties = rule->properties();
-        if (properties.isEmpty() && !matchRequest.includeEmptyRules)
-            return;
         // FIXME: Exposing the non-standard getMatchedCSSRules API to web is the only reason this is needed.
         if (m_sameOriginOnly && !ruleData.hasDocumentSecurityOrigin())
             return;