add ImageGenerator::NewFromData to porting layer

src/image/SkImage.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmap.h"
 #include "SkCanvas.h"
+#include "SkImageGenerator.h"
 #include "SkImagePriv.h"
 #include "SkImage_Base.h"
 #include "SkReadPixelsRec.h"
 #include "SkString.h"
 #include "SkSurface.h"
 
 uint32_t SkImage::NextUniqueID() {
     static int32_t gUniqueID;
 
     // never return 0;
@@ skipping 45 matching lines @@
 }
 
 SkData* SkImage::encode(SkImageEncoder::Type type, int quality) const {
     SkBitmap bm;
     if (as_IB(this)->getROPixels(&bm)) {
         return SkImageEncoder::EncodeData(bm, type, quality);
     }
     return NULL;
 }
 
+SkImage* SkImage::NewFromData(SkData* data) {
+    if (NULL == data) {
+        return NULL;
+    }
+    SkImageGenerator* generator = SkImageGenerator::NewFromData(data);
+    return generator ? SkImage::NewFromGenerator(generator) : NULL;
+}
+
 SkSurface* SkImage::newSurface(const SkImageInfo& info, const SkSurfaceProps* props) const {
     if (NULL == props) {
         props = &as_IB(this)->props();
     }
     return as_IB(this)->onNewSurface(info, *props);
 }
 
 const char* SkImage::toString(SkString* str) const {
     str->appendf("image: (id:%d (%d, %d) %s)", this->uniqueID(), this->width(), this->height(),
                  this->isOpaque() ? "opaque" : "");
@@ skipping 25 matching lines @@
     SkBitmap bm;
     bm.installPixels(dstInfo, dstPixels, dstRowBytes);
     SkCanvas canvas(bm);
 
     SkPaint paint;
     paint.setXfermodeMode(SkXfermode::kSrc_Mode);
     canvas.drawImage(this, -SkIntToScalar(srcX), -SkIntToScalar(srcY), &paint);
 
     return true;
 }