remove sk_atomic_inc

Change-Id: I4960b1cd055daf44637e95825f82cb7fe2ce134a
Reviewed-on: https://skia-review.googlesource.com/c/174285
Commit-Queue: Mike Klein <mtklein@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
diff --git a/src/gpu/GrOpList.cpp b/src/gpu/GrOpList.cpp
index dd889e8..b1ccc82 100644
--- a/src/gpu/GrOpList.cpp
+++ b/src/gpu/GrOpList.cpp
@@ -13,15 +13,13 @@
 #include "GrRenderTargetPriv.h"
 #include "GrSurfaceProxy.h"
 #include "GrTextureProxyPriv.h"
-
-#include "SkAtomics.h"
+#include <atomic>
 
 uint32_t GrOpList::CreateUniqueID() {
-    static int32_t gUniqueID = SK_InvalidUniqueID;
+    static std::atomic<uint32_t> nextID{1};
     uint32_t id;
-    // Loop in case our global wraps around, as we never want to return a 0.
     do {
-        id = static_cast<uint32_t>(sk_atomic_inc(&gUniqueID) + 1);
+        id = nextID++;
     } while (id == SK_InvalidUniqueID);
     return id;
 }