Make "priv" classes for GrTexure and GrSurface.

bench/GrResourceCacheBench.cpp

Index: bench/GrResourceCacheBench.cpp
diff --git a/bench/GrResourceCacheBench.cpp b/bench/GrResourceCacheBench.cpp
index d86ccf4b0b218d6340e8caf2dbb90f2d35adb407..234a62624cb0a5325abb94abdb283c79980935f4 100644
--- a/bench/GrResourceCacheBench.cpp
+++ b/bench/GrResourceCacheBench.cpp
@@ -14,6 +14,7 @@
 #include "GrResourceCache.h"
 #include "GrStencilBuffer.h"
 #include "GrTexture.h"
+#include "GrTexturePriv.h"
 #include "SkCanvas.h"
 
 enum {
@@ -62,7 +63,7 @@ public:
     }
 
     static GrResourceKey ComputeKey(const GrTextureDesc& desc) {
-        return GrTextureImpl::ComputeScratchKey(desc);
+        return GrTexturePriv::ComputeScratchKey(desc);
     }
 
     int fID;