Expand SkMessageBus to support different unique key types

Bug: skia:11728
Change-Id: I16fb8250fa5c04ce3fe369a50d0c61a0bee46811
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/383696
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
diff --git a/include/gpu/GrDirectContext.h b/include/gpu/GrDirectContext.h
index 6df48de..022bad5 100644
--- a/include/gpu/GrDirectContext.h
+++ b/include/gpu/GrDirectContext.h
@@ -793,7 +793,7 @@
 
     class DirectContextID {
     public:
-        static GrDirectContext::DirectContextID NextID();
+        static GrDirectContext::DirectContextID Next();
 
         DirectContextID() : fID(SK_InvalidUniqueID) {}