De-classicify Browser

Removes the hard run-time dependency on WebViewClassic.
(Still needs visisbility of it to build though)
This is needed to enable chromium webview testing.

Change-Id: I290b6b23b2eac525537ebc3ef8007d681a67a169
diff --git a/src/com/android/browser/XLargeUi.java b/src/com/android/browser/XLargeUi.java
index 3b8245a..df7a586 100644
--- a/src/com/android/browser/XLargeUi.java
+++ b/src/com/android/browser/XLargeUi.java
@@ -117,7 +117,7 @@
 
     void stopWebViewScrolling() {
         BrowserWebView web = (BrowserWebView) mUiController.getCurrentWebView();
-        if (web != null) {
+        if (web != null && BrowserWebView.isClassic()) {
             WebViewClassic.fromWebView(web).stopScroll();
         }
     }