small fix for clip mask cache clear

src/gpu/GrClipMaskManager.h

Index: src/gpu/GrClipMaskManager.h
diff --git a/src/gpu/GrClipMaskManager.h b/src/gpu/GrClipMaskManager.h
index c38e1405b08e5f09b1e7c5354d7fb0eac88217bb..20b7fdc0778ec923b669d4e74822dc9645b0cafd 100644
--- a/src/gpu/GrClipMaskManager.h
+++ b/src/gpu/GrClipMaskManager.h
@@ -80,12 +80,6 @@ public:
         return kAlpha_ClipMaskType == fCurrClipMaskType;
     }
 
-    void invalidateStencilMask() {
-        if (kStencil_ClipMaskType == fCurrClipMaskType) {
-            fCurrClipMaskType = kNone_ClipMaskType;
-        }
-    }
-
     GrContext* getContext() {
         return fAACache.getContext();
     }