Minor build fixes for aura/touchui

ui/base/dragdrop/os_exchange_data_provider_aura.cc

Index: ui/base/dragdrop/os_exchange_data_provider_aura.cc
diff --git a/ui/base/dragdrop/os_exchange_data_provider_aura.cc b/ui/base/dragdrop/os_exchange_data_provider_aura.cc
index 18b4128ebe7cdfe7e49a16fc166ef690457647f7..349b89fff9317ab6bef42dd5de07d7c9b1962810 100644
--- a/ui/base/dragdrop/os_exchange_data_provider_aura.cc
+++ b/ui/base/dragdrop/os_exchange_data_provider_aura.cc
@@ -69,7 +69,8 @@ OSExchangeData::Provider* OSExchangeData::CreateProvider() {
 }
 
 // static
-void* OSExchangeData::RegisterCustomFormat(const std::string& type) {
+OSExchangeData::CustomFormat
+OSExchangeData::RegisterCustomFormat(const std::string& type) {
   // TODO(davemoore) Implement this for aura.
   return NULL;
 }