Linux: Fix some NULL versus 0 issues to appease gcc-4.5.

webkit/glue/plugins/pepper_scrollbar.cc

 // Copyright (c) 2010 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/glue/plugins/pepper_scrollbar.h"
 
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "third_party/ppapi/c/ppp_scrollbar.h"
 #include "third_party/WebKit/WebKit/chromium/public/WebInputEvent.h"
@@ skipping 10 matching lines @@
 using WebKit::WebRect;
 using WebKit::WebScrollbar;
 
 namespace pepper {
 
 namespace {
 
 PP_Resource Create(PP_Instance instance_id, bool vertical) {
   PluginInstance* instance = PluginInstance::FromPPInstance(instance_id);
   if (!instance)
-    return NULL;
+    return 0;
 
   scoped_refptr<Scrollbar> scrollbar(new Scrollbar(instance, vertical));
   return scrollbar->GetReference();
 }
 
 bool IsScrollbar(PP_Resource resource) {
   return !!Resource::GetAs<Scrollbar>(resource);
 }
 
 uint32_t GetThickness() {
@@ skipping 177 matching lines @@
   PP_Rect pp_rect;
   pp_rect.point.x = dirty_.x();
   pp_rect.point.y = dirty_.y();
   pp_rect.size.width = dirty_.width();
   pp_rect.size.height = dirty_.height();
   dirty_ = gfx::Rect();
   Invalidate(&pp_rect);
 }
 
 }  // namespace pepper