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

webkit/glue/plugins/pepper_device_context_2d.cc

Index: webkit/glue/plugins/pepper_device_context_2d.cc
diff --git a/webkit/glue/plugins/pepper_device_context_2d.cc b/webkit/glue/plugins/pepper_device_context_2d.cc
index 45ed9ee3f8b220a7a60709027770afa489c52355..8407da3a8e820a344a0e5ab1c089786a71e19b26 100644
--- a/webkit/glue/plugins/pepper_device_context_2d.cc
+++ b/webkit/glue/plugins/pepper_device_context_2d.cc
@@ -68,11 +68,11 @@ PP_Resource Create(PP_Module module_id,
                    bool is_always_opaque) {
   PluginModule* module = PluginModule::FromPPModule(module_id);
   if (!module)
-    return NULL;
+    return 0;
 
   scoped_refptr<DeviceContext2D> context(new DeviceContext2D(module));
   if (!context->Init(size->width, size->height, is_always_opaque))
-    return NULL;
+    return 0;
   return context->GetReference();
 }