Move webcursors code from webkit/ to content.

webkit/common/cursors/webcursor_null.cc

-// Copyright (c) 2012 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.
-
-#include "webkit/common/cursors/webcursor.h"
-
-const ui::PlatformCursor WebCursor::GetPlatformCursor() {
-  return NULL;
-}
-
-void WebCursor::SetDisplayInfo(const gfx::Display& display) {
-  return;
-}
-
-void WebCursor::InitPlatformData() {
-}
-
-bool WebCursor::SerializePlatformData(Pickle* pickle) const {
-  return true;
-}
-
-bool WebCursor::DeserializePlatformData(PickleIterator* iter) {
-  return true;
-}
-
-bool WebCursor::IsPlatformDataEqual(const WebCursor& other) const {
-  return true;
-}
-
-void WebCursor::CleanupPlatformData() {
-}
-
-void WebCursor::CopyPlatformData(const WebCursor& other) {
-}