Make GrSurfaceProxy derive from GrNonAtomicRef and remove GrIORefProxy.

Also, expose GrNonAtomicRef's ref count. Since it's non-atomic and not
thread-safe it seems fine.

Change-Id: I5cf48e60d32094354955b2614cfeebbb4c1ecf2a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/238059
Auto-Submit: Brian Salomon <bsalomon@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
diff --git a/tests/ProxyRefTest.cpp b/tests/ProxyRefTest.cpp
index 4629557..b5cf20e 100644
--- a/tests/ProxyRefTest.cpp
+++ b/tests/ProxyRefTest.cpp
@@ -23,7 +23,7 @@
                        GrTextureProxy* proxy,
                        int32_t expectedProxyRefs,
                        int32_t expectedBackingRefs) {
-    int32_t actualProxyRefs = proxy->priv().getProxyRefCnt();
+    int32_t actualProxyRefs = proxy->refCnt();
     int32_t actualBackingRefs = proxy->testingOnly_getBackingRefCnt();
 
     SkASSERT(actualProxyRefs == expectedProxyRefs);