Add subsetting to SkScaledCodec

dm/DMSrcSink.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 "DMSrcSink.h"
 #include "SamplePipeControllers.h"
 #include "SkCodec.h"
@@ skipping 68 matching lines @@
 bool BRDSrc::veto(SinkFlags flags) const {
     // No need to test to non-raster or indirect backends.
     return flags.type != SinkFlags::kRaster
         || flags.approach != SinkFlags::kDirect;
 }
 
 static SkBitmapRegionDecoderInterface* create_brd(Path path,
         SkBitmapRegionDecoderInterface::Strategy strategy) {
     SkAutoTUnref<SkData> encoded(SkData::NewFromFileName(path.c_str()));
     if (!encoded) {
-        return NULL;
+        return nullptr;
     }
     return SkBitmapRegionDecoderInterface::CreateBitmapRegionDecoder(new SkMemoryStream(encoded),
             strategy);
 }
 
 Error BRDSrc::draw(SkCanvas* canvas) const {
     SkColorType colorType = canvas->imageInfo().colorType();
     if (kRGB_565_SkColorType == colorType &&
             CodecSrc::kGetFromCanvas_DstColorType != fDstColorType) {
         return Error::Nonfatal("Testing non-565 to 565 is uninteresting.");
     }
     switch (fDstColorType) {
         case CodecSrc::kGetFromCanvas_DstColorType:
             break;
         case CodecSrc::kIndex8_Always_DstColorType:
             colorType = kIndex_8_SkColorType;
             break;
         case CodecSrc::kGrayscale_Always_DstColorType:
             colorType = kGray_8_SkColorType;
             break;
     }
 
     SkAutoTDelete<SkBitmapRegionDecoderInterface> brd(create_brd(fPath, fStrategy));
     if (nullptr == brd.get()) {
         return Error::Nonfatal(SkStringPrintf("Could not create brd for %s.", fPath.c_str()));
     }
 
+    if (!brd->conversionSupported(colorType)) {
+        return Error::Nonfatal("Cannot convert to color type.\n");
+    }
+
     const uint32_t width = brd->width();
     const uint32_t height = brd->height();
     // Visually inspecting very small output images is not necessary.
     if ((width / fSampleSize <= 10 || height / fSampleSize <= 10) && 1 != fSampleSize) {
         return Error::Nonfatal("Scaling very small images is uninteresting.");
     }
     switch (fMode) {
         case kFullImage_Mode: {
             SkAutoTDelete<SkBitmap> bitmap(brd->decodeRegion(0, 0, width, height, fSampleSize,
                     colorType));
@@ skipping 110 matching lines @@
     // let the GPU handle it.
     return flags.type != SinkFlags::kRaster
         || flags.approach != SinkFlags::kDirect;
 }
 
 Error CodecSrc::draw(SkCanvas* canvas) const {
     SkAutoTUnref<SkData> encoded(SkData::NewFromFileName(fPath.c_str()));
     if (!encoded) {
         return SkStringPrintf("Couldn't read %s.", fPath.c_str());
     }
-    SkAutoTDelete<SkCodec> codec(NULL);
+    SkAutoTDelete<SkCodec> codec(nullptr);
     if (kScaledCodec_Mode == fMode) {
         codec.reset(SkScaledCodec::NewFromData(encoded));
         // TODO (msarett): This should fall through to a fatal error once we support scaled
         //                 codecs for all image types.
         if (nullptr == codec.get()) {
             return Error::Nonfatal(SkStringPrintf("Couldn't create scaled codec for %s.",
                     fPath.c_str()));
         }
     } else {
         codec.reset(SkCodec::NewFromData(encoded));
@@ skipping 944 matching lines @@
             skr.visit<void>(i, drawsAsSingletonPictures);
         }
         SkAutoTUnref<SkPicture> macroPic(macroRec.endRecordingAsPicture());
 
         canvas->drawPicture(macroPic);
         return "";
     });
 }
 
 }  // namespace DM