No need to re-parse empty set of injected stylesheets.

Source/core/dom/Document.cpp

Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index 31fa3eaf232ae0fcb181779ffe66f2b9ab14d0ea..097fcdee5d1b5631dd43407737e2bb6396d8387a 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -709,7 +709,7 @@ void Document::setCompatibilityMode(CompatibilityMode mode)
     selectorQueryCache().invalidate();
     if (inQuirksMode() != wasInQuirksMode) {
         // All injected stylesheets have to reparse using the different mode.
-        m_styleEngine->invalidateInjectedStyleSheetCache();
+        m_styleEngine->compatibilityModeChanged();
     }
 }