Port uses of SkLazyPtr to SkOncePtr.

src/utils/SkEventTracer.cpp

Index: src/utils/SkEventTracer.cpp
diff --git a/src/utils/SkEventTracer.cpp b/src/utils/SkEventTracer.cpp
index 1c916ed2f666851fba78f1ec42b3ab74919d5cb5..32a0207c23ebaa0f3d0ac9edd7a29688a67c0e23 100644
--- a/src/utils/SkEventTracer.cpp
+++ b/src/utils/SkEventTracer.cpp
@@ -7,7 +7,7 @@
 
 #include "SkAtomics.h"
 #include "SkEventTracer.h"
-#include "SkLazyPtr.h"
+#include "SkOncePtr.h"
 
 #include <stdlib.h>
 
@@ -41,7 +41,7 @@ class SkDefaultEventTracer : public SkEventTracer {
 
 // We prefer gUserTracer if it's been set, otherwise we fall back on gDefaultTracer.
 static SkEventTracer* gUserTracer = nullptr;
-SK_DECLARE_STATIC_LAZY_PTR(SkDefaultEventTracer, gDefaultTracer);
+SK_DECLARE_STATIC_ONCE_PTR(SkDefaultEventTracer, gDefaultTracer);
 
 void SkEventTracer::SetInstance(SkEventTracer* tracer) {
     SkASSERT(nullptr == sk_atomic_load(&gUserTracer, sk_memory_order_acquire));
@@ -54,5 +54,5 @@ SkEventTracer* SkEventTracer::GetInstance() {
     if (SkEventTracer* tracer = sk_atomic_load(&gUserTracer, sk_memory_order_acquire)) {
         return tracer;
     }
-    return gDefaultTracer.get();
+    return gDefaultTracer.get([]{ return new SkDefaultEventTracer; });
 }