SkImage method for detecting lazy decoding

src/lazy/SkCachingPixelRef.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkCachingPixelRef_DEFINED
 #define SkCachingPixelRef_DEFINED
 
@@ skipping 32 matching lines @@
 protected:
     virtual ~SkCachingPixelRef();
     bool onNewLockPixels(LockRec*) override;
     void onUnlockPixels() override;
     bool onLockPixelsAreWritable() const override { return false; }
 
     SkData* onRefEncodedData() override {
         return fImageGenerator->refEncodedData();
     }
 
+    bool onIsLazyGenerated() const override { return true; }
+
 private:
     SkImageGenerator* const fImageGenerator;
     bool                    fErrorInDecoding;
     const size_t            fRowBytes;
 
     SkBitmap                fLockedBitmap;
 
     SkCachingPixelRef(const SkImageInfo&, SkImageGenerator*, size_t rowBytes);
 
     typedef SkPixelRef INHERITED;
 };
 
 #endif  // SkCachingPixelRef_DEFINED