Revert of remvoe duplicate impl for SkImageInfo flattening

src/lazy/SkDiscardablePixelRef.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 SkDiscardablePixelRef_DEFINED
 #define SkDiscardablePixelRef_DEFINED
 
 #include "SkDiscardableMemory.h"
 #include "SkImageGenerator.h"
 #include "SkImageInfo.h"
 #include "SkPixelRef.h"
 
 class SkDiscardablePixelRef : public SkPixelRef {
 public:
     SK_DECLARE_UNFLATTENABLE_OBJECT()
 
 protected:
     ~SkDiscardablePixelRef();
-
-    virtual bool onNewLockPixels(LockRec*) SK_OVERRIDE;
+    virtual void* onLockPixels(SkColorTable**) SK_OVERRIDE;
     virtual void onUnlockPixels() SK_OVERRIDE;
     virtual bool onLockPixelsAreWritable() const SK_OVERRIDE { return false; }
 
     virtual SkData* onRefEncodedData() SK_OVERRIDE {
         return fGenerator->refEncodedData();
     }
 
 private:
     SkImageGenerator* const fGenerator;
     SkDiscardableMemory::Factory* const fDMFactory;
+    const SkImageInfo fInfo;
+    const size_t fSize;  // size of memory to be allocated
     const size_t fRowBytes;
     // These const members should not change over the life of the
     // PixelRef, since the SkBitmap doesn't expect them to change.
 
     SkDiscardableMemory* fDiscardableMemory;
 
     /* Takes ownership of SkImageGenerator. */
     SkDiscardablePixelRef(SkImageGenerator* generator,
                           const SkImageInfo& info,
+                          size_t size,
                           size_t rowBytes,
                           SkDiscardableMemory::Factory* factory);
-
     friend bool SkInstallDiscardablePixelRef(SkImageGenerator*,
                                              SkBitmap*,
                                              SkDiscardableMemory::Factory*);
-
     typedef SkPixelRef INHERITED;
 };
-
 #endif  // SkDiscardablePixelRef_DEFINED