Use SkTLazy to hold path in SkClipStack::Element

include/core/SkTLazy.h

Index: include/core/SkTLazy.h
diff --git a/include/core/SkTLazy.h b/include/core/SkTLazy.h
index 2147b6681fa601dff47b8554eeea58fc5c70fc1e..a291e22a137692226425776dc9efaafb860836bb 100644
--- a/include/core/SkTLazy.h
+++ b/include/core/SkTLazy.h
@@ -75,6 +75,16 @@ public:
     }
 
     /**
+     * Destroy the lazy object (if it was created via init() or set())
+     */
+    void reset() {
+        if (this->isValid()) {
+            fPtr->~T();
+            fPtr = NULL;
+        }
+    }
+
+    /**
      *  Returns true if a valid object has been initialized in the SkTLazy,
      *  false otherwise.
      */