Explicitly coerce PostDispatchAction to uint32_t in DispatchEvent()

ui/base/dragdrop/os_exchange_data_provider_aurax11.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 "ui/base/dragdrop/os_exchange_data_provider_aurax11.h"
 
 #include "base/logging.h"
 #include "base/memory/ref_counted_memory.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 500 matching lines @@
     const PlatformEvent& event) {
   return event->xany.window == x_window_;
 }
 
 uint32_t OSExchangeDataProviderAuraX11::DispatchEvent(
     const PlatformEvent& event) {
   XEvent* xev = event;
   switch (xev->type) {
     case SelectionRequest:
       selection_owner_.OnSelectionRequest(*xev);
-      return ui::POST_DISPATCH_STOP_PROPAGATION;
+      return ui::kPostDispatchStopPropagation;
     default:
       NOTIMPLEMENTED();
   }
-  return ui::POST_DISPATCH_NONE;
+  return ui::kPostDispatchNone;
 }
 
 bool OSExchangeDataProviderAuraX11::GetPlainTextURL(GURL* url) const {
   base::string16 text;
   if (GetString(&text)) {
     GURL test_url(text);
     if (test_url.is_valid()) {
       *url = test_url;
       return true;
     }
   }
 
   return false;
 }
 
 std::vector< ::Atom> OSExchangeDataProviderAuraX11::GetTargets() const {
   return format_map_.GetTypes();
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 // OSExchangeData, public:
 
 // static
 OSExchangeData::Provider* OSExchangeData::CreateProvider() {
   return new OSExchangeDataProviderAuraX11();
 }
 
 }  // namespace ui