Fill incomplete images in SkCodec parent class

tools/SkBitmapRegionDecoderInterface.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmapRegionCanvas.h"
 #include "SkBitmapRegionDecoderInterface.h"
 #include "SkBitmapRegionSampler.h"
@@ skipping 11 matching lines @@
                 return nullptr;
             }
             if (!decoder->buildTileIndex(stream, &width, &height)) {
                 SkDebugf("Error: Could not build tile index.\n");
                 delete decoder;
                 return nullptr;
             }
             return new SkBitmapRegionSampler(decoder, width, height);
         }
         case kCanvas_Strategy: {
-            SkCodec* decoder = SkCodec::NewFromStream(stream);
-            if (nullptr == decoder) {
+            SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(stream));
+            if (nullptr == codec) {
                 SkDebugf("Error: Failed to create decoder.\n");
                 return nullptr;
             }
-            switch (decoder->getScanlineOrder()) {
+            switch (codec->getScanlineOrder()) {
                 case SkCodec::kTopDown_SkScanlineOrder:
                 case SkCodec::kNone_SkScanlineOrder:
                     break;
                 default:
                     SkDebugf("Error: Scanline ordering not supported.\n");
                     return nullptr;
             }
-            return new SkBitmapRegionCanvas(decoder);
+            return new SkBitmapRegionCanvas(codec.detach());
         }
         default:
             SkASSERT(false);
             return nullptr;
     }
 }