Avoid parsing css text if there are identical inline style blocks.

Source/core/dom/StyleElement.cpp

Index: Source/core/dom/StyleElement.cpp
diff --git a/Source/core/dom/StyleElement.cpp b/Source/core/dom/StyleElement.cpp
index 596ea53c73efd25e4f95c2a87d481cd2eb30e422..dde3edfe3b42acd86d92769f89350c8cfd478f30 100644
--- a/Source/core/dom/StyleElement.cpp
+++ b/Source/core/dom/StyleElement.cpp
@@ -112,6 +112,7 @@ void StyleElement::process(Element* element)
 void StyleElement::clearSheet()
 {
     ASSERT(m_sheet);
+
     m_sheet.release()->clearOwnerNode();
 }
 
@@ -135,15 +136,10 @@ void StyleElement::createSheet(Element* e, const String& text)
         MediaQueryEvaluator screenEval("screen", true);
         MediaQueryEvaluator printEval("print", true);
         if (screenEval.eval(mediaQueries.get()) || printEval.eval(mediaQueries.get())) {
-            document.styleEngine()->addPendingSheet();
             m_loading = true;
-
             TextPosition startPosition = m_startPosition == TextPosition::belowRangePosition() ? TextPosition::minimumPosition() : m_startPosition;
-            m_sheet = CSSStyleSheet::createInline(e, KURL(), startPosition, document.inputEncoding());
+            m_sheet = StyleEngine::createSheet(e, text, startPosition, m_createdByParser);
             m_sheet->setMediaQueries(mediaQueries.release());
-            m_sheet->setTitle(e->title());
-            m_sheet->contents()->parseStringAtPosition(text, startPosition, m_createdByParser);
-
             m_loading = false;
         }
     }