Change SkImageDecoders to take an SkStreamRewindable.

tests/ImageDecodingTest.cpp

 /*
  * Copyright 2013 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 "SkColor.h"
@@ skipping 176 matching lines @@
             //SkDebugf("about to decode \"%s\"\n", filename.c_str());
             compare_unpremul(reporter, filename);
         } while (iter.next(&basename));
     } else {
         SkDebugf("Failed to find any files :(\n");
     }
 }
 
 #ifdef SK_DEBUG
 // Create a stream containing a bitmap encoded to Type type.
-static SkStream* create_image_stream(SkImageEncoder::Type type) {
+static SkMemoryStream* create_image_stream(SkImageEncoder::Type type) {
     SkBitmap bm;
     const int size = 50;
     bm.setConfig(SkBitmap::kARGB_8888_Config, size, size);
     bm.allocPixels();
     SkCanvas canvas(bm);
     SkPoint points[2] = {
         { SkIntToScalar(0), SkIntToScalar(0) },
         { SkIntToScalar(size), SkIntToScalar(size) }
     };
     SkColor colors[2] = { SK_ColorWHITE, SK_ColorBLUE };
@@ skipping 18 matching lines @@
 static void test_stream_life() {
     const SkImageEncoder::Type gTypes[] = {
 #ifdef SK_BUILD_FOR_ANDROID
         SkImageEncoder::kJPEG_Type,
         SkImageEncoder::kPNG_Type,
 #endif
         SkImageEncoder::kWEBP_Type,
     };
     for (size_t i = 0; i < SK_ARRAY_COUNT(gTypes); ++i) {
         //SkDebugf("encoding to %i\n", i);
-        SkAutoTUnref<SkStream> stream(create_image_stream(gTypes[i]));
+        SkAutoTUnref<SkMemoryStream> stream(create_image_stream(gTypes[i]));
         if (NULL == stream.get()) {
             SkDebugf("no stream\n");
             continue;
         }
         SkAutoTDelete<SkImageDecoder> decoder(SkImageDecoder::Factory(stream));
         if (NULL == decoder.get()) {
             SkDebugf("no decoder\n");
             continue;
         }
         int width, height;
@@ skipping 14 matching lines @@
     test_unpremul(reporter);
     test_pref_config_table(reporter);
 #ifdef SK_DEBUG
     test_stream_life();
 #endif
 }
 
 #include "TestClassDef.h"
 DEFINE_TESTCLASS("ImageDecoding", ImageDecodingTestClass,
                  test_imageDecodingTests)