Require explicit selection of traits for LazyInstance

ipc/ipc_sync_channel.cc

Index: ipc/ipc_sync_channel.cc
diff --git a/ipc/ipc_sync_channel.cc b/ipc/ipc_sync_channel.cc
index f92d1edd772b347966dde4232dde699fba5b77d6..840c89d94871d0e80094336e03f81f2df7799dd2 100644
--- a/ipc/ipc_sync_channel.cc
+++ b/ipc/ipc_sync_channel.cc
@@ -214,8 +214,8 @@ class SyncChannel::ReceivedSyncMsgQueue :
   }
 
   // Holds a pointer to the per-thread ReceivedSyncMsgQueue object.
-  static base::LazyInstance<base::ThreadLocalPointer<ReceivedSyncMsgQueue> >
-      lazy_tls_ptr_;
+  static base::LazyInstance<base::ThreadLocalPointer<ReceivedSyncMsgQueue>>::
+      DestructorAtExit lazy_tls_ptr_;
 
   // Called on the ipc thread to check if we can unblock any current Send()
   // calls based on a queued reply.
@@ -312,7 +312,8 @@ class SyncChannel::ReceivedSyncMsgQueue :
   std::unique_ptr<mojo::SyncHandleWatcher> sync_dispatch_watcher_;
 };
 
-base::LazyInstance<base::ThreadLocalPointer<SyncChannel::ReceivedSyncMsgQueue> >
+base::LazyInstance<base::ThreadLocalPointer<
+    SyncChannel::ReceivedSyncMsgQueue>>::DestructorAtExit
     SyncChannel::ReceivedSyncMsgQueue::lazy_tls_ptr_ =
         LAZY_INSTANCE_INITIALIZER;