[WebView] Enable scrolling in fullscreen.

android_webview/java/src/org/chromium/android_webview/NullAwViewMethods.java

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.android_webview;
 
 import android.content.res.Configuration;
 import android.graphics.Canvas;
 import android.graphics.Paint;
 import android.graphics.Rect;
@@ skipping 109 matching lines @@
 
     @Override
     public void onVisibilityChanged(View changedView, int visibility) {
         // Intentional no-op.
     }
 
     @Override
     public void onWindowVisibilityChanged(int visibility) {
         // Intentional no-op.
     }
+
+    @Override
+    public void onContainerViewScrollChanged(int l, int t, int oldl, int oldt) {
+        // Intentional no-op.
+    }
+
+    @Override
+    public void onContainerViewOverScrolled(int scrollX, int scrollY, boolean clampedX,
+            boolean clampedY) {
+        // Intentional no-op.
+    }
+
+    @Override
+    public int computeHorizontalScrollRange() {
+        return 0;
+    }
+
+    @Override
+    public int computeHorizontalScrollOffset() {
+        return 0;
+    }
+
+    @Override
+    public int computeVerticalScrollRange() {
+        return 0;
+    }
+
+    @Override
+    public int computeVerticalScrollOffset() {
+        return 0;
+    }
+
+    @Override
+    public int computeVerticalScrollExtent() {
+        return 0;
+    }
+
+    @Override
+    public void computeScroll() {
+        // Intentional no-op.
+    }
 }