Refactored cacheID in preparation for clip mask caching changes

http://codereview.appspot.com/6458089/



git-svn-id: http://skia.googlecode.com/svn/trunk@5002 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/gpu/GrTexture.h b/include/gpu/GrTexture.h
index d4a7cc6..2ccd301 100644
--- a/include/gpu/GrTexture.h
+++ b/include/gpu/GrTexture.h
@@ -10,6 +10,7 @@
 #define GrTexture_DEFINED
 
 #include "GrSurface.h"
+#include "GrCacheID.h"
 
 class GrRenderTarget;
 class GrResourceKey;
@@ -30,6 +31,7 @@
 
 public:
     SK_DECLARE_INST_COUNT(GrTexture)
+    GR_DECLARE_RESOURCE_CACHE_TYPE()
 
     // from GrResource
     /**