One allocation for an SkData which makes a copy.

include/core/SkWeakRefCnt.h

Index: include/core/SkWeakRefCnt.h
===================================================================
--- include/core/SkWeakRefCnt.h	(revision 9702)
+++ include/core/SkWeakRefCnt.h	(working copy)
@@ -23,7 +23,7 @@
     getRefCnt() > 1.
 
     In addition to strong ownership, an owner may instead obtain a weak
-    reference by calling weak_ref(). A call to weak_ref() must be balanced my a
+    reference by calling weak_ref(). A call to weak_ref() must be balanced by a
     call to weak_unref(). To obtain a strong reference from a weak reference,
     call try_ref(). If try_ref() returns true, the owner's pointer is now also
     a strong reference on which unref() must be called. Note that this does not
@@ -74,7 +74,7 @@
     int32_t getWeakCnt() const { return fWeakCnt; }
 
     void validate() const {
-        SkRefCnt::validate();
+        this->INHERITED::validate();

[reed1, 2013/06/21 19:00:36]

please please please consider landing this and related changes independent of
this SkData effort. We keep iterating on SkData, but these sorts of changes are
fine, and unrelated (afaik).

         SkASSERT(fWeakCnt > 0);
     }
 
@@ -120,7 +120,7 @@
             // so our destructor won't complain
             fWeakCnt = 1;
 #endif
-            SkRefCnt::internal_dispose();
+            this->INHERITED::internal_dispose();
         }
     }