Remove WebContents::InsertCSS since it is unused

content/public/android/java/src/org/chromium/content_public/browser/WebContents.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.content_public.browser;
 
 import android.graphics.Bitmap;
 import android.graphics.Rect;
 import android.os.Parcelable;
 
@@ skipping 91 matching lines @@
      */
     void selectAll();
 
     /**
      * Clear the selection. This includes the cursor which is a zero-sized selection, and keyboard
      * will be hidden as a result.
      */
     void unselect();
 
     /**
-     * Inserts css into main frame's document.
-     */
-    void insertCSS(String css);
-
-    /**
      * To be called when the ContentView is hidden.
      */
     void onHide();
 
     /**
      * To be called when the ContentView is shown.
      */
     void onShow();
 
     /**
@@ skipping 248 matching lines @@
      *                 0 means unlimited.
      * @param bypassCache If true, {@link url} is requested from the server even if it is present in
      *                 the browser cache.
      * @param callback The callback which will be called when the bitmaps are received from the
      *                 renderer.
      * @return The unique id of the download request
      */
     public int downloadImage(String url, boolean isFavicon, int maxBitmapSize,
             boolean bypassCache, ImageDownloadCallback callback);
 }