Navigation transitions: Added "addStyleSheetByURL" function to insert stylesheet links.

Source/web/WebLocalFrameImpl.cpp

Index: Source/web/WebLocalFrameImpl.cpp
diff --git a/Source/web/WebLocalFrameImpl.cpp b/Source/web/WebLocalFrameImpl.cpp
index d0c099b10d3316a056370afd074d54345b09eafd..11c22c9d43cb10e8155f0daac6597885a796ff95 100644
--- a/Source/web/WebLocalFrameImpl.cpp
+++ b/Source/web/WebLocalFrameImpl.cpp
@@ -1284,6 +1284,17 @@ void WebLocalFrameImpl::extendSelectionAndDelete(int before, int after)
     frame()->inputMethodController().extendSelectionAndDelete(before, after);
 }
 
+void WebLocalFrameImpl::addStyleSheetByURL(const WebString& url)
+{
+    RefPtr<Element> styleElement = frame()->document()->createElement(HTMLNames::linkTag, false);
+
+    styleElement->setAttribute(HTMLNames::typeAttr, "text/css");
+    styleElement->setAttribute(HTMLNames::relAttr, "stylesheet");
+    styleElement->setAttribute(HTMLNames::hrefAttr, url);
+
+    frame()->document()->head()->appendChild(styleElement.release(), IGNORE_EXCEPTION);
+}
+
 void WebLocalFrameImpl::setCaretVisible(bool visible)
 {
     frame()->selection().setCaretVisible(visible);