Remove the concept of user stylesheets.

LayoutTests/css3/device-adapt/viewport-height-extend-to-zoom.html

Index: LayoutTests/css3/device-adapt/viewport-height-extend-to-zoom.html
diff --git a/LayoutTests/css3/device-adapt/viewport-height-extend-to-zoom.html b/LayoutTests/css3/device-adapt/viewport-height-extend-to-zoom.html
index d2a05c94b6ff1cd220d0f0b044e4cf7cf7ee1722..b5279d78bfc20f4b57c57c2a1c5fff16d2693f27 100644
--- a/LayoutTests/css3/device-adapt/viewport-height-extend-to-zoom.html
+++ b/LayoutTests/css3/device-adapt/viewport-height-extend-to-zoom.html
@@ -14,7 +14,7 @@
         }, "Check that window.testRunner is present. Required to add a user stylesheet.");
 
         if (window.testRunner) {
-            testRunner.addUserStyleSheet("@viewport { width: -internal-extend-to-zoom 980px; min-zoom: 0.25; max-zoom: 5; height: auto ; zoom: auto; user-zoom: zoom; orientation: auto }", true);
+            testRunner.injectStyleSheet("@viewport { width: -internal-extend-to-zoom 980px; min-zoom: 0.25; max-zoom: 5; height: auto ; zoom: auto; user-zoom: zoom; orientation: auto }", true);
         }
     </script>
 </head>