change SkStreams to work with sk_sp<SkData> instead of SkData*

tests/PDFJpegEmbedTest.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 "SkCanvas.h"
 #include "SkData.h"
 #include "SkDocument.h"
@@ skipping 60 matching lines @@
     canvas->clear(SK_ColorLTGRAY);
 
     SkBitmap bm1(bitmap_from_data(mandrillData.get()));
     canvas->drawBitmap(bm1, 65.0, 0.0, nullptr);
     SkBitmap bm2(bitmap_from_data(cmykData.get()));
     canvas->drawBitmap(bm2, 0.0, 512.0, nullptr);
 
     canvas->flush();
     document->endPage();
     document->close();
-    sk_sp<SkData> pdfData(pdf.copyToData());
+    sk_sp<SkData> pdfData(pdf.detachAsData());
     SkASSERT(pdfData);
-    pdf.reset();
 
     REPORTER_ASSERT(r, is_subset_of(mandrillData.get(), pdfData.get()));
 
     // This JPEG uses a nonstandard colorspace - it can not be
     // embedded into the PDF directly.
     REPORTER_ASSERT(r, !is_subset_of(cmykData.get(), pdfData.get()));
     ////////////////////////////////////////////////////////////////////////////
     pdf.reset();
     document = SkDocument::MakePDF(&pdf);
     canvas = document->beginPage(642, 1028);
 
     canvas->clear(SK_ColorLTGRAY);
 
     sk_sp<SkImage> im1(SkImage::MakeFromEncoded(mandrillData));
     canvas->drawImage(im1.get(), 65.0, 0.0, nullptr);
     sk_sp<SkImage> im2(SkImage::MakeFromEncoded(cmykData));
     canvas->drawImage(im2.get(), 0.0, 512.0, nullptr);
 
     canvas->flush();
     document->endPage();
     document->close();
-    pdfData.reset(pdf.copyToData());
+    pdfData = pdf.detachAsData();
     SkASSERT(pdfData);
-    pdf.reset();
 
     REPORTER_ASSERT(r, is_subset_of(mandrillData.get(), pdfData.get()));
 
     // This JPEG uses a nonstandard colorspace - it can not be
     // embedded into the PDF directly.
     REPORTER_ASSERT(r, !is_subset_of(cmykData.get(), pdfData.get()));
 }
 
 DEF_TEST(SkPDF_JpegIdentification, r) {
     static struct {
@@ skipping 116 matching lines @@
             "\377\330\377\340\0\20JFIF\0\1\1\0\0\1\0\1\0\0\377\333\0C\0\10\6\6\7"
             "\6\5\10\7\7\7\t\t\10\n\14\24\r\14\13\13\14\31\22\23\17\24\35\32\37"
             "\36\35\32\34\34 $.' \",#\34\34(7),01444\37'9=82<.342\377\333\0C\1\t"
             "\t\t\14\13\14\30\r\r\0302!\34!222222222222222222222222222222222222"
             "22222222222222\377\300\0\21\10\2\0\2\0\2\1\"\0\2\21\1\3\21\001";
         size_t jpegLength = 177;
         auto data = SkData::MakeWithoutCopy(jpeg, jpegLength);
         REPORTER_ASSERT(r, !SkIsJFIF(data.get(), &info));
     }
 }