Switch SkAutoMalloc to SkAutoTMalloc to avoid cast

include/private/SkTemplates.h

Index: include/private/SkTemplates.h
diff --git a/include/private/SkTemplates.h b/include/private/SkTemplates.h
index 533cb264d163ee7354f1e53de7bac4a2de36cd61..c1fd4cbca62e681cdc8e3334ab9338631b7633bf 100644
--- a/include/private/SkTemplates.h
+++ b/include/private/SkTemplates.h
@@ -272,9 +272,10 @@ public:
     }
 
     /** Resize the memory area pointed to by the current ptr without preserving contents. */
-    void reset(size_t count) {
+    T* reset(size_t count) {
         sk_free(fPtr);
         fPtr = (T*)sk_malloc_flags(count * sizeof(T), SK_MALLOC_THROW);
+        return fPtr;
     }
 
     T* get() const { return fPtr; }
@@ -296,6 +297,13 @@ public:
     }
 
     /**
+     *  Releases the block back to the heap
+     */
+    void free() {
+        this->reset(0);
+    }
+
+    /**
      *  Transfer ownership of the ptr to the caller, setting the internal
      *  pointer to NULL. Note that this differs from get(), which also returns
      *  the pointer, but it does not transfer ownership.