Make RenderObject::style() return a const object

Source/core/rendering/RenderQuote.cpp

Index: Source/core/rendering/RenderQuote.cpp
diff --git a/Source/core/rendering/RenderQuote.cpp b/Source/core/rendering/RenderQuote.cpp
index 38bdcb109d06a25264553edcaeaf61d6738abd75..857d1d004208946e0408f05b0c87e93c9e7a62fb 100644
--- a/Source/core/rendering/RenderQuote.cpp
+++ b/Source/core/rendering/RenderQuote.cpp
@@ -272,11 +272,11 @@ void RenderQuote::updateText()
 
     RenderTextFragment* fragment = findFragmentChild();
     if (fragment) {
-        fragment->setStyle(style());
+        fragment->setStyle(deprecatedMutableStyle());
         fragment->setContentString(m_text.impl());
     } else {
         fragment = new RenderTextFragment(&document(), m_text.impl());
-        fragment->setStyle(style());
+        fragment->setStyle(deprecatedMutableStyle());
         addChild(fragment);
     }
 }