Fix up a ton of implicit memory_order_seq_cst for unique id gen

Change-Id: Icfbaa3129f5b45b5053c4f3444ff904c188b211a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/332725
Reviewed-by: Mike Klein <mtklein@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Adlai Holler <adlai@google.com>
diff --git a/src/gpu/GrClipStack.cpp b/src/gpu/GrClipStack.cpp
index abab6b7..98de71b 100644
--- a/src/gpu/GrClipStack.cpp
+++ b/src/gpu/GrClipStack.cpp
@@ -192,7 +192,7 @@
 
     uint32_t id;
     do {
-        id = nextID++;
+        id = nextID.fetch_add(1, std::memory_order_relaxed);
     } while (id < kFirstUnreservedGenID);
     return id;
 }