Retract Gr*Priv.h includes a bit

Change-Id: Ic2bfd83b6e6bcc5ea1591427683085637eb5a6cc
Reviewed-on: https://skia-review.googlesource.com/41360
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
diff --git a/tests/ProxyTest.cpp b/tests/ProxyTest.cpp
index 453cb5e..edf54f6 100644
--- a/tests/ProxyTest.cpp
+++ b/tests/ProxyTest.cpp
@@ -15,7 +15,7 @@
 #include "GrRenderTargetPriv.h"
 #include "GrRenderTargetProxy.h"
 #include "GrResourceProvider.h"
-#include "GrSurfaceProxy.h"
+#include "GrSurfaceProxyPriv.h"
 #include "GrTexture.h"
 #include "GrTextureProxy.h"