Make leak counters thread-safe

gm/convexpaths.cpp

Index: gm/convexpaths.cpp
diff --git a/gm/convexpaths.cpp b/gm/convexpaths.cpp
index 8eb4cba49d7a1c80fd2ac35991702cba177daefb..91afbfeba3dfc2d3c7bb94c7e6d6dd60fdf6193e 100644
--- a/gm/convexpaths.cpp
+++ b/gm/convexpaths.cpp
@@ -9,9 +9,9 @@
 #include "SkRandom.h"
 #include "SkTArray.h"
 
-class SkOnce : SkNoncopyable {
+class SkDoOnce : SkNoncopyable {
 public:
-    SkOnce() { fDidOnce = false; }
+    SkDoOnce() { fDidOnce = false; }
 
     bool needToDo() const { return !fDidOnce; }
     bool alreadyDone() const { return fDidOnce; }
@@ -27,7 +27,7 @@ private:
 namespace skiagm {
 
 class ConvexPathsGM : public GM {
-    SkOnce fOnce;
+    SkDoOnce fOnce;
 public:
     ConvexPathsGM() {
         this->setBGColor(0xFF000000);