Pull texture-backed bitmap resampler out of GrTextureParamsAdjuster code into its own class.

src/core/SkImageCacherator.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkImageCacherator_DEFINED
 #define SkImageCacherator_DEFINED
 
@@ skipping 68 matching lines @@
         operator SkImageGenerator*() const { return fCacher->fNotThreadSafeGenerator; }
     };
 
     SkMutex                         fMutexForGenerator;
     SkAutoTDelete<SkImageGenerator> fNotThreadSafeGenerator;
 
     const SkImageInfo   fInfo;
     const SkIPoint      fOrigin;
     const uint32_t      fUniqueID;
 
-    friend class Cacherator_GrTextureParamsAdjuster;
+    friend class Cacherator_GrTextureMaker;
 };
 
 #endif