Replace uses of GR_DEBUG by SK_DEBUG.

src/gpu/GrTextureAccess.cpp

Index: src/gpu/GrTextureAccess.cpp
diff --git a/src/gpu/GrTextureAccess.cpp b/src/gpu/GrTextureAccess.cpp
index 122a2090aad508c4b79dcd05ae2cef57c0cc6c9d..e4b078698defb932f4bdf5bf3f316f18b4724677 100644
--- a/src/gpu/GrTextureAccess.cpp
+++ b/src/gpu/GrTextureAccess.cpp
@@ -10,7 +10,7 @@
 #include "GrTexture.h"
 
 GrTextureAccess::GrTextureAccess() {
-#if GR_DEBUG
+#ifdef SK_DEBUG
     memcpy(fSwizzle, "void", 5);
     fSwizzleMask = 0xbeeffeed;
 #endif