add ImageGenerator::NewFromData to porting layer

gm/astcbitmap.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "gm.h"
 
 #include "Resources.h"
 #include "SkCanvas.h"
 #include "SkData.h"
-#include "SkDecodingImageGenerator.h"
+#include "SkImageGenerator.h"
 #include "SkImageDecoder.h"
 #include "SkOSFile.h"
 #include "SkTextureCompressor.h"
 
 static const char *kASTCFilenames[] = {
     "mandrill_128x128_4x4.astc",    // kASTC_4x4_Format
     "mandrill_130x128_5x4.astc",    // kASTC_5x4_Format
     "mandrill_130x130_5x5.astc",    // kASTC_5x5_Format
     "mandrill_132x130_6x5.astc",    // kASTC_6x5_Format
     "mandrill_132x132_6x6.astc",    // kASTC_6x6_Format
@@ skipping 45 matching lines @@
                     continue;
                 }
 
                 SkAutoTUnref<SkData> fileData(SkData::NewFromFileName(filename.c_str()));
                 if (NULL == fileData) {
                     SkDebugf("Could not open the file. Did you forget to set the resourcePath?\n");
                     return;
                 }
 
                 SkBitmap bm;
-                if (!SkInstallDiscardablePixelRef(
-                        SkDecodingImageGenerator::Create(
-                            fileData, SkDecodingImageGenerator::Options()), &bm)) {
+                if (!SkInstallDiscardablePixelRef(fileData, &bm)) {
                     SkDebugf("Could not install discardable pixel ref.\n");
                     return;
                 }
 
                 const SkScalar bmX = static_cast<SkScalar>(i*kBitmapDimension);
                 const SkScalar bmY = static_cast<SkScalar>(j*kBitmapDimension);
                 canvas->drawBitmap(bm, bmX, bmY);
             }
         }
     }
 
 private:
     static const int kGMDimension = 600;
     static const int kBitmapDimension = kGMDimension/4;
 
     typedef GM INHERITED;
 };
 
 }  // namespace skiagm
 
 //////////////////////////////////////////////////////////////////////////////
 
 DEF_GM( return SkNEW(skiagm::ASTCBitmapGM); )