rolling tree back to its state as of r2169 to see if that fixes Windows buildbots

git-svn-id: http://skia.googlecode.com/svn/trunk@2179 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gpu/src/GrBinHashKey.h b/gpu/src/GrBinHashKey.h
index ceaef7a..936eab0 100644
--- a/gpu/src/GrBinHashKey.h
+++ b/gpu/src/GrBinHashKey.h
@@ -36,7 +36,7 @@
         return *this;
     }
 
-    ~GrBinHashKey() {
+    virtual ~GrBinHashKey() {
     }
 
     void setKeyData(const uint32_t *data) {