Make the onScrollChange implementation a no-op.

Chromium calls this method from ContentViewCore, but it shouldn't
be called this way for the WebView.

Change-Id: I01592cd3b2fc1020c23a692cc00a4a7f1bf81d07
diff --git a/chromium/java/com/android/webview/chromium/WebViewChromium.java b/chromium/java/com/android/webview/chromium/WebViewChromium.java
index 3368d58..b582539 100644
--- a/chromium/java/com/android/webview/chromium/WebViewChromium.java
+++ b/chromium/java/com/android/webview/chromium/WebViewChromium.java
@@ -1992,9 +1992,9 @@
 
         @Override
         public void onScrollChanged(int l, int t, int oldl, int oldt) {
-            mWebViewPrivate.setScrollXRaw(l);
-            mWebViewPrivate.setScrollYRaw(t);
-            mWebViewPrivate.onScrollChanged(l, t, oldl, oldt);
+	    // Intentional no-op.
+            // Chromium calls this directly to trigger accessibility events. That isn't needed
+            // for WebView since super_scrollTo invokes onScrollChanged for us.
         }
 
         @Override