Remove unused activeAuthorStyleSheets method.

R=mstensho@opera.com

Review URL: https://codereview.chromium.org/1498593004

Cr-Commit-Position: refs/heads/master@{#362959}

third_party/WebKit/Source/core/dom/StyleEngine.cpp

@@ -146,11 +146,6 @@ const WillBeHeapVector<RefPtrWillBeMember<StyleSheet>>& StyleEngine::styleSheets
     return ensureStyleSheetCollectionFor(treeScope)->styleSheetsForStyleSheetList();
 }
 
-const WillBeHeapVector<RefPtrWillBeMember<CSSStyleSheet>>& StyleEngine::activeAuthorStyleSheets() const
-{
-    return documentStyleSheetCollection()->activeAuthorStyleSheets();
-}
-
 void StyleEngine::combineCSSFeatureFlags(const RuleFeatureSet& features)
 {
     // Delay resetting the flags until after next style recalc since unapplying the style may not work without these set (this is true at least with before/after).

third_party/WebKit/Source/core/dom/StyleEngine.h

@@ -79,7 +79,6 @@ public:
 #endif
 
     const WillBeHeapVector<RefPtrWillBeMember<StyleSheet>>& styleSheetsForStyleSheetList(TreeScope&);
-    const WillBeHeapVector<RefPtrWillBeMember<CSSStyleSheet>>& activeAuthorStyleSheets() const;
 
     const WillBeHeapVector<RefPtrWillBeMember<CSSStyleSheet>>& documentAuthorStyleSheets() const { return m_authorStyleSheets; }