Delete dead subset benches from nanobench

This approach to subset decoding is no longer supported.
We have replaced it with an implementation that does not
depend on forked libraries.
https://codereview.chromium.org/1406153015/

BUG=skia:

Review URL: https://codereview.chromium.org/1430493005

8 files changed, 176 insertions, 329 deletions

diff --git a/bench/BitmapRegionDecoderBench.cpp b/bench/BitmapRegionDecoderBench.cpp
index 1d2a0b91f7..4d9dec03aa 100644
--- a/bench/BitmapRegionDecoderBench.cpp
+++ b/bench/BitmapRegionDecoderBench.cpp
@@ -24,9 +24,6 @@ BitmapRegionDecoderBench::BitmapRegionDecoderBench(const char* baseName, SkData*
     // Choose a useful name for the region decoding strategy
     const char* strategyName;
     switch (strategy) {
-        case SkBitmapRegionDecoder::kOriginal_Strategy:
-            strategyName = "Original";
-            break;
         case SkBitmapRegionDecoder::kCanvas_Strategy:
             strategyName = "Canvas";
             break;
diff --git a/bench/nanobench.cpp b/bench/nanobench.cpp
index 95d017c6da..0987cb7cfe 100644
--- a/bench/nanobench.cpp
+++ b/bench/nanobench.cpp
@@ -107,8 +107,6 @@ DEFINE_bool(loopSKP, true, "Loop SKPs like we do for micro benches?");
 DEFINE_int32(flushEvery, 10, "Flush --outResultsFile every Nth run.");
 DEFINE_bool(resetGpuContext, true, "Reset the GrContext before running each test.");
 DEFINE_bool(gpuStats, false, "Print GPU stats after each gpu benchmark?");
-DEFINE_bool(pngBuildTileIndex, false, "If supported, use png buildTileIndex/decodeSubset.");
-DEFINE_bool(jpgBuildTileIndex, false, "If supported, use jpg buildTileIndex/decodeSubset.");
 
 static double now_ms() { return SkTime::GetNSecs() * 1e-6; }
 
@@ -499,35 +497,22 @@ static Target* is_enabled(Benchmark* bench, const Config& config) {
 
 /*
  * We only run our subset benches on files that are supported by BitmapRegionDecoder:
- * i.e. PNG, JPEG, and WEBP. We do *not* test WEBP when using codec, since we do not
- * have a scanline decoder for WEBP, which is necessary for running the subset bench.
- * (Another bench must be used to test WEBP, which decodes subsets natively.)
+ * i.e. PNG, JPEG, and WEBP. We do *not* test WEBP, since we do not have a scanline
+ * decoder for WEBP, which is necessary for running the subset bench. (Another bench
+ * must be used to test WEBP, which decodes subsets natively.)
  */
-static bool run_subset_bench(const SkString& path, bool useCodec) {
+static bool run_subset_bench(const SkString& path) {
     static const char* const exts[] = {
-        "jpg", "jpeg",
-        "JPG", "JPEG",
+        "jpg", "jpeg", "png",
+        "JPG", "JPEG", "PNG",
     };
 
-    if (useCodec || FLAGS_jpgBuildTileIndex) {
-        for (uint32_t i = 0; i < SK_ARRAY_COUNT(exts); i++) {
-            if (path.endsWith(exts[i])) {
-                return true;
-            }
+    for (uint32_t i = 0; i < SK_ARRAY_COUNT(exts); i++) {
+        if (path.endsWith(exts[i])) {
+            return true;
         }
     }
 
-    // Test png in SkCodec, and optionally on SkImageDecoder. SkImageDecoder is
-    // disabled by default because it leaks memory.
-    // https://bug.skia.org/4360
-    if ((useCodec || FLAGS_pngBuildTileIndex) && (path.endsWith("png") || path.endsWith("PNG"))) {
-        return true;
-    }
-
-    if (!useCodec && (path.endsWith("webp") || path.endsWith("WEBP"))) {
-        return true;
-    }
-
     return false;
 }
 
@@ -535,49 +520,31 @@ static bool run_subset_bench(const SkString& path, bool useCodec) {
  * Returns true if set up for a subset decode succeeds, false otherwise
  * If the set-up succeeds, the width and height parameters will be set
  */
-static bool valid_subset_bench(const SkString& path, SkColorType colorType, bool useCodec,
+static bool valid_subset_bench(const SkString& path, SkColorType colorType,
         int* width, int* height) {
     SkAutoTUnref<SkData> encoded(SkData::NewFromFileName(path.c_str()));
     SkAutoTDelete<SkMemoryStream> stream(new SkMemoryStream(encoded));
 
-    // Check that we can create a codec or image decoder.
-    if (useCodec) {
-        SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(stream.detach()));
-        if (nullptr == codec) {
-            SkDebugf("Could not create codec for %s.  Skipping bench.\n", path.c_str());
-            return false;
-        }
+    // Check that we can create a codec.
+    SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(stream.detach()));
+    if (nullptr == codec) {
+        SkDebugf("Could not create codec for %s.  Skipping bench.\n", path.c_str());
+        return false;
+    }
 
-        // These will be initialized by SkCodec if the color type is kIndex8 and
-        // unused otherwise.
-        SkPMColor colors[256];
-        int colorCount;
-        const SkImageInfo info = codec->getInfo().makeColorType(colorType);
-        if (codec->startScanlineDecode(info, nullptr, colors, &colorCount) != SkCodec::kSuccess)
-        {
-            SkDebugf("Could not create scanline decoder for %s with color type %s.  "
-                    "Skipping bench.\n", path.c_str(), color_type_to_str(colorType));
-            return false;
-        }
-        *width = info.width();
-        *height = info.height();
-    } else {
-        SkAutoTDelete<SkImageDecoder> decoder(SkImageDecoder::Factory(stream));
-        if (nullptr == decoder) {
-            SkDebugf("Could not create decoder for %s.  Skipping bench.\n", path.c_str());
-            return false;
-        }
-        //FIXME: See https://bug.skia.org/3921
-        if (kIndex_8_SkColorType == colorType || kGray_8_SkColorType == colorType) {
-            SkDebugf("Cannot use image subset decoder for %s with color type %s.  "
-                    "Skipping bench.\n", path.c_str(), color_type_to_str(colorType));
-            return false;
-        }
-        if (!decoder->buildTileIndex(stream.detach(), width, height)) {
-            SkDebugf("Could not build tile index for %s.  Skipping bench.\n", path.c_str());
-            return false;
-        }
+    // These will be initialized by SkCodec if the color type is kIndex8 and
+    // unused otherwise.
+    SkPMColor colors[256];
+    int colorCount;
+    const SkImageInfo info = codec->getInfo().makeColorType(colorType);
+    if (codec->startScanlineDecode(info, nullptr, colors, &colorCount) != SkCodec::kSuccess)
+    {
+        SkDebugf("Could not create scanline decoder for %s with color type %s.  "
+                "Skipping bench.\n", path.c_str(), color_type_to_str(colorType));
+        return false;
     }
+    *width = info.width();
+    *height = info.height();
 
     // Check if the image is large enough for a meaningful subset benchmark.
     if (*width <= 512 && *height <= 512) {
@@ -603,11 +570,6 @@ static bool valid_brd_bench(SkData* encoded, SkBitmapRegionDecoder::Strategy str
             1, colorType, false)) {
         return false;
     }
-    if (colorType != bitmap.colorType()) {
-        // This indicates that conversion to the requested color type is not supported for the
-        // particular image.
-        return false;
-    }
 
     if (sampleSize * minOutputSize > (uint32_t) brd->width() || sampleSize * minOutputSize >
             (uint32_t) brd->height()) {
@@ -648,7 +610,6 @@ public:
                       , fCurrentBRDImage(0)
                       , fCurrentColorType(0)
                       , fCurrentSubsetType(0)
-                      , fUseCodec(0)
                       , fCurrentBRDStrategy(0)
                       , fCurrentBRDSampleSize(0)
                       , fCurrentAnimSKP(0) {
@@ -898,69 +859,60 @@ public:
         }
 
         // Run the SubsetBenches
-        bool useCodecOpts[] = { true, false };
-        while (fUseCodec < 2) {
-            bool useCodec = useCodecOpts[fUseCodec];
+        while (fCurrentSubsetImage < fImages.count()) {
             fSourceType = "image";
-            fBenchType = useCodec ? "skcodec" : "skimagedecoder";
-            while (fCurrentSubsetImage < fImages.count()) {
-                const SkString& path = fImages[fCurrentSubsetImage];
-                if (!run_subset_bench(path, useCodec)) {
-                    fCurrentSubsetImage++;
-                    continue;
-                }
-                while (fCurrentColorType < fColorTypes.count()) {
-                    SkColorType colorType = fColorTypes[fCurrentColorType];
-                    while (fCurrentSubsetType <= kLast_SubsetType) {
-                        int width = 0;
-                        int height = 0;
-                        int currentSubsetType = fCurrentSubsetType++;
-                        if (valid_subset_bench(path, colorType, useCodec, &width, &height)) {
-                            switch (currentSubsetType) {
-                                case kTopLeft_SubsetType:
-                                    return new SubsetSingleBench(path, colorType, width/3,
-                                            height/3, 0, 0, useCodec);
-                                case kTopRight_SubsetType:
-                                    return new SubsetSingleBench(path, colorType, width/3,
-                                            height/3, 2*width/3, 0, useCodec);
-                                case kMiddle_SubsetType:
-                                    return new SubsetSingleBench(path, colorType, width/3,
-                                            height/3, width/3, height/3, useCodec);
-                                case kBottomLeft_SubsetType:
-                                    return new SubsetSingleBench(path, colorType, width/3,
-                                            height/3, 0, 2*height/3, useCodec);
-                                case kBottomRight_SubsetType:
-                                    return new SubsetSingleBench(path, colorType, width/3,
-                                            height/3, 2*width/3, 2*height/3, useCodec);
-                                case kTranslate_SubsetType:
-                                    return new SubsetTranslateBench(path, colorType, 512, 512,
-                                            useCodec);
-                                case kZoom_SubsetType:
-                                    return new SubsetZoomBench(path, colorType, 512, 512,
-                                            useCodec);
-                            }
-                        } else {
-                            break;
+            fBenchType = "skcodec";
+            const SkString& path = fImages[fCurrentSubsetImage];
+            if (!run_subset_bench(path)) {
+                fCurrentSubsetImage++;
+                continue;
+            }
+            while (fCurrentColorType < fColorTypes.count()) {
+                SkColorType colorType = fColorTypes[fCurrentColorType];
+                while (fCurrentSubsetType <= kLast_SubsetType) {
+                    int width = 0;
+                    int height = 0;
+                    int currentSubsetType = fCurrentSubsetType++;
+                    if (valid_subset_bench(path, colorType, &width, &height)) {
+                        switch (currentSubsetType) {
+                            case kTopLeft_SubsetType:
+                                return new SubsetSingleBench(path, colorType, width/3,
+                                        height/3, 0, 0);
+                            case kTopRight_SubsetType:
+                                return new SubsetSingleBench(path, colorType, width/3,
+                                        height/3, 2*width/3, 0);
+                            case kMiddle_SubsetType:
+                                return new SubsetSingleBench(path, colorType, width/3,
+                                        height/3, width/3, height/3);
+                            case kBottomLeft_SubsetType:
+                                return new SubsetSingleBench(path, colorType, width/3,
+                                        height/3, 0, 2*height/3);
+                            case kBottomRight_SubsetType:
+                                return new SubsetSingleBench(path, colorType, width/3,
+                                        height/3, 2*width/3, 2*height/3);
+                            case kTranslate_SubsetType:
+                                return new SubsetTranslateBench(path, colorType, 512, 512);
+                            case kZoom_SubsetType:
+                                return new SubsetZoomBench(path, colorType, 512, 512);
                         }
+                    } else {
+                        break;
                     }
-                    fCurrentSubsetType = 0;
-                    fCurrentColorType++;
                 }
-                fCurrentColorType = 0;
-                fCurrentSubsetImage++;
+                fCurrentSubsetType = 0;
+                fCurrentColorType++;
             }
-            fCurrentSubsetImage = 0;
-            fUseCodec++;
+            fCurrentColorType = 0;
+            fCurrentSubsetImage++;
         }
 
         // Run the BRDBenches
         // We will benchmark multiple BRD strategies.
         static const struct {
             SkBitmapRegionDecoder::Strategy    fStrategy;
-            const char*                                 fName;
+            const char*                        fName;
         } strategies[] = {
-            { SkBitmapRegionDecoder::kOriginal_Strategy,    "BRD" },
-            { SkBitmapRegionDecoder::kCanvas_Strategy,      "BRD_canvas" },
+            { SkBitmapRegionDecoder::kCanvas_Strategy,       "BRD_canvas" },
             { SkBitmapRegionDecoder::kAndroidCodec_Strategy, "BRD_android_codec" },
         };
 
@@ -989,24 +941,6 @@ public:
                 const SkBitmapRegionDecoder::Strategy strategy =
                         strategies[fCurrentBRDStrategy].fStrategy;
 
-                if (SkBitmapRegionDecoder::kOriginal_Strategy == strategy) {
-                    // Disable png and jpeg for SkImageDecoder:
-                    if (!FLAGS_jpgBuildTileIndex) {
-                        if (path.endsWith("JPEG") || path.endsWith("JPG") ||
-                            path.endsWith("jpeg") || path.endsWith("jpg"))
-                        {
-                            fCurrentBRDStrategy++;
-                            continue;
-                        }
-                    }
-                    if (!FLAGS_pngBuildTileIndex) {
-                        if (path.endsWith("PNG") || path.endsWith("png")) {
-                            fCurrentBRDStrategy++;
-                            continue;
-                        }
-                    }
-                }
-
                 while (fCurrentColorType < fColorTypes.count()) {
                     while (fCurrentBRDSampleSize < (int) SK_ARRAY_COUNT(sampleSizes)) {
                         while (fCurrentSubsetType <= kLastSingle_SubsetType) {
@@ -1133,7 +1067,6 @@ private:
     int fCurrentBRDImage;
     int fCurrentColorType;
     int fCurrentSubsetType;
-    int fUseCodec;
     int fCurrentBRDStrategy;
     int fCurrentBRDSampleSize;
     int fCurrentAnimSKP;
diff --git a/bench/subset/SubsetSingleBench.cpp b/bench/subset/SubsetSingleBench.cpp
index 47a897fd83..e30dd51e78 100644
--- a/bench/subset/SubsetSingleBench.cpp
+++ b/bench/subset/SubsetSingleBench.cpp
@@ -26,14 +26,12 @@ SubsetSingleBench::SubsetSingleBench(const SkString& path,
                                      uint32_t subsetWidth,
                                      uint32_t subsetHeight,
                                      uint32_t offsetLeft,
-                                     uint32_t offsetTop,
-                                     bool useCodec)
+                                     uint32_t offsetTop)
     : fColorType(colorType)
     , fSubsetWidth(subsetWidth)
     , fSubsetHeight(subsetHeight)
     , fOffsetLeft(offsetLeft)
     , fOffsetTop(offsetTop)
-    , fUseCodec(useCodec)
 {
     // Parse the filename
     SkString baseName = SkOSPath::Basename(path.c_str());
@@ -41,7 +39,7 @@ SubsetSingleBench::SubsetSingleBench(const SkString& path,
     // Choose an informative color name
     const char* colorName = color_type_to_str(fColorType);
 
-    fName.printf("%sSubsetSingle_%dx%d +%d_+%d_%s_%s", fUseCodec ? "Codec" : "Image", fSubsetWidth,
+    fName.printf("CodecSubsetSingle_%dx%d +%d_+%d_%s_%s", fSubsetWidth,
             fSubsetHeight, fOffsetLeft, fOffsetTop, baseName.c_str(), colorName);
 
     // Perform the decode setup
@@ -62,42 +60,30 @@ void SubsetSingleBench::onDraw(int n, SkCanvas* canvas) {
     // used, it will be initialized by the codec.
     int colorCount;
     SkPMColor colors[256];
-    if (fUseCodec) {
-        for (int count = 0; count < n; count++) {
-            SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(fStream->duplicate()));
-            SkASSERT(SkCodec::kOutOfOrder_SkScanlineOrder != codec->getScanlineOrder());
-            const SkImageInfo info = codec->getInfo().makeColorType(fColorType);
+    for (int count = 0; count < n; count++) {
+        SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(fStream->duplicate()));
+        SkASSERT(SkCodec::kOutOfOrder_SkScanlineOrder != codec->getScanlineOrder());
+        const SkImageInfo info = codec->getInfo().makeColorType(fColorType);
 
-            // The scanline decoder will handle subsetting in the x-dimension.
-            SkIRect subset = SkIRect::MakeXYWH(fOffsetLeft, 0, fSubsetWidth,
-                    codec->getInfo().height());
-            SkCodec::Options options;
-            options.fSubset = &subset;
+        // The scanline decoder will handle subsetting in the x-dimension.
+        SkIRect subset = SkIRect::MakeXYWH(fOffsetLeft, 0, fSubsetWidth,
+                codec->getInfo().height());
+        SkCodec::Options options;
+        options.fSubset = &subset;
 
-            SkDEBUGCODE(SkCodec::Result result =)
-            codec->startScanlineDecode(info, &options, colors, &colorCount);
-            SkASSERT(result == SkCodec::kSuccess);
+        SkDEBUGCODE(SkCodec::Result result =)
+        codec->startScanlineDecode(info, &options, colors, &colorCount);
+        SkASSERT(result == SkCodec::kSuccess);
 
-            SkBitmap bitmap;
-            SkImageInfo subsetInfo = info.makeWH(fSubsetWidth, fSubsetHeight);
-            alloc_pixels(&bitmap, subsetInfo, colors, colorCount);
+        SkBitmap bitmap;
+        SkImageInfo subsetInfo = info.makeWH(fSubsetWidth, fSubsetHeight);
+        alloc_pixels(&bitmap, subsetInfo, colors, colorCount);
 
-            SkDEBUGCODE(bool success = ) codec->skipScanlines(fOffsetTop);
-            SkASSERT(success);
+        SkDEBUGCODE(bool success = ) codec->skipScanlines(fOffsetTop);
+        SkASSERT(success);
 
-            SkDEBUGCODE(uint32_t lines = ) codec->getScanlines(bitmap.getPixels(), fSubsetHeight,
-                    bitmap.rowBytes());
-            SkASSERT(lines == fSubsetHeight);
-        }
-    } else {
-        for (int count = 0; count < n; count++) {
-            SkAutoTDelete<SkImageDecoder> decoder(SkImageDecoder::Factory(fStream));
-            int width, height;
-            SkAssertResult(decoder->buildTileIndex(fStream->duplicate(), &width, &height));
-            SkBitmap bitmap;
-            SkIRect rect = SkIRect::MakeXYWH(fOffsetLeft, fOffsetTop, fSubsetWidth,
-                    fSubsetHeight);
-            SkAssertResult(decoder->decodeSubset(&bitmap, rect, fColorType));
-        }
+        SkDEBUGCODE(uint32_t lines = ) codec->getScanlines(bitmap.getPixels(), fSubsetHeight,
+                bitmap.rowBytes());
+        SkASSERT(lines == fSubsetHeight);
     }
 }
diff --git a/bench/subset/SubsetSingleBench.h b/bench/subset/SubsetSingleBench.h
index 62e281ad67..da325ac429 100644
--- a/bench/subset/SubsetSingleBench.h
+++ b/bench/subset/SubsetSingleBench.h
@@ -25,8 +25,7 @@ public:
                       uint32_t subsetWidth,
                       uint32_t subsetHeight,
                       uint32_t offsetLeft,
-                      uint32_t offsetTop,
-                      bool useCodec);
+                      uint32_t offsetTop);
 
 protected:
     const char* onGetName() override;
@@ -40,7 +39,6 @@ private:
     const uint32_t                fSubsetHeight;
     const uint32_t                fOffsetLeft;
     const uint32_t                fOffsetTop;
-    const bool                    fUseCodec;
     SkAutoTDelete<SkMemoryStream> fStream;
     typedef Benchmark INHERITED;
 };
diff --git a/bench/subset/SubsetTranslateBench.cpp b/bench/subset/SubsetTranslateBench.cpp
index d8da6db566..bcf1227454 100644
--- a/bench/subset/SubsetTranslateBench.cpp
+++ b/bench/subset/SubsetTranslateBench.cpp
@@ -24,12 +24,10 @@
 SubsetTranslateBench::SubsetTranslateBench(const SkString& path,
                                            SkColorType colorType,
                                            uint32_t subsetWidth,
-                                           uint32_t subsetHeight,
-                                           bool useCodec)
+                                           uint32_t subsetHeight)
     : fColorType(colorType)
     , fSubsetWidth(subsetWidth)
     , fSubsetHeight(subsetHeight)
-    , fUseCodec(useCodec)
 {
     // Parse the filename
     SkString baseName = SkOSPath::Basename(path.c_str());
@@ -37,7 +35,7 @@ SubsetTranslateBench::SubsetTranslateBench(const SkString& path,
     // Choose an informative color name
     const char* colorName = color_type_to_str(fColorType);
 
-    fName.printf("%sSubsetTranslate_%dx%d_%s_%s", fUseCodec ? "Codec" : "Image", fSubsetWidth,
+    fName.printf("CodecSubsetTranslate_%dx%d_%s_%s", fSubsetWidth,
             fSubsetHeight, baseName.c_str(), colorName);
     
     // Perform the decode setup
@@ -68,76 +66,42 @@ void SubsetTranslateBench::onDraw(int n, SkCanvas* canvas) {
     // used, it will be initialized by the codec.
     int colorCount = 256;
     SkPMColor colors[256];
-    if (fUseCodec) {
-        for (int count = 0; count < n; count++) {
-            SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(fStream->duplicate()));
-            SkASSERT(SkCodec::kOutOfOrder_SkScanlineOrder != codec->getScanlineOrder());
-            const SkImageInfo info = codec->getInfo().makeColorType(fColorType);
-
-            SkBitmap bitmap;
-            // Note that we use the same bitmap for all of the subsets.
-            // It might be larger than necessary for the end subsets.
-            SkImageInfo subsetInfo = info.makeWH(fSubsetWidth, fSubsetHeight);
-            alloc_pixels(&bitmap, subsetInfo, colors, colorCount);
-
-            for (int x = 0; x < info.width(); x += fSubsetWidth) {
-                for (int y = 0; y < info.height(); y += fSubsetHeight) {
-                    const uint32_t currSubsetWidth =
-                            x + (int) fSubsetWidth > info.width() ?
-                            info.width() - x : fSubsetWidth;
-                    const uint32_t currSubsetHeight =
-                            y + (int) fSubsetHeight > info.height() ?
-                            info.height() - y : fSubsetHeight;
-
-                    // The scanline decoder will handle subsetting in the x-dimension.
-                    SkIRect subset = SkIRect::MakeXYWH(x, 0, currSubsetWidth,
-                            codec->getInfo().height());
-                    SkCodec::Options options;
-                    options.fSubset = &subset;
-
-                    SkDEBUGCODE(SkCodec::Result result =)
-                    codec->startScanlineDecode(info, &options, get_colors(&bitmap), &colorCount);
-                    SkASSERT(SkCodec::kSuccess == result);
-
-                    SkDEBUGCODE(bool success =) codec->skipScanlines(y);
-                    SkASSERT(success);
-
-                    SkDEBUGCODE(uint32_t lines =) codec->getScanlines(bitmap.getPixels(),
-                            currSubsetHeight, bitmap.rowBytes());
-                    SkASSERT(currSubsetHeight == lines);
-                }
-            }
-        }
-    } else {
-        // We create a color table here to satisfy allocPixels() when the output
-        // type is kIndex8.  It's okay that this is uninitialized since we never
-        // use it.
-        SkAutoTUnref<SkColorTable> colorTable(new SkColorTable(colors, 0));
-        for (int count = 0; count < n; count++) {
-            int width, height;
-            SkAutoTDelete<SkImageDecoder> decoder(SkImageDecoder::Factory(fStream));
-            SkAssertResult(decoder->buildTileIndex(fStream->duplicate(), &width, &height));
-            SkBitmap bitmap;
-            // Note that we use the same bitmap for all of the subsets.
-            // It might be larger than necessary for the end subsets.
-            // If we do not include this step, decodeSubset() would allocate space
-            // for the pixels automatically, but this would not allow us to reuse the
-            // same bitmap as the other subsets.  We want to reuse the same bitmap
-            // because it gives a more fair comparison with SkCodec and is a common
-            // use case of BitmapRegionDecoder.
-            bitmap.allocPixels(SkImageInfo::Make(fSubsetWidth, fSubsetHeight,
-                    fColorType, kOpaque_SkAlphaType), nullptr, colorTable);
-
-            for (int x = 0; x < width; x += fSubsetWidth) {
-                for (int y = 0; y < height; y += fSubsetHeight) {
-                    const uint32_t currSubsetWidth = x + (int) fSubsetWidth > width ?
-                            width - x : fSubsetWidth;
-                    const uint32_t currSubsetHeight = y + (int) fSubsetHeight > height ?
-                            height - y : fSubsetHeight;
-                    SkIRect rect = SkIRect::MakeXYWH(x, y, currSubsetWidth,
-                            currSubsetHeight);
-                    SkAssertResult(decoder->decodeSubset(&bitmap, rect, fColorType));
-                }
+    for (int count = 0; count < n; count++) {
+        SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(fStream->duplicate()));
+        SkASSERT(SkCodec::kOutOfOrder_SkScanlineOrder != codec->getScanlineOrder());
+        const SkImageInfo info = codec->getInfo().makeColorType(fColorType);
+
+        SkBitmap bitmap;
+        // Note that we use the same bitmap for all of the subsets.
+        // It might be larger than necessary for the end subsets.
+        SkImageInfo subsetInfo = info.makeWH(fSubsetWidth, fSubsetHeight);
+        alloc_pixels(&bitmap, subsetInfo, colors, colorCount);
+
+        for (int x = 0; x < info.width(); x += fSubsetWidth) {
+            for (int y = 0; y < info.height(); y += fSubsetHeight) {
+                const uint32_t currSubsetWidth =
+                        x + (int) fSubsetWidth > info.width() ?
+                        info.width() - x : fSubsetWidth;
+                const uint32_t currSubsetHeight =
+                        y + (int) fSubsetHeight > info.height() ?
+                        info.height() - y : fSubsetHeight;
+
+                // The scanline decoder will handle subsetting in the x-dimension.
+                SkIRect subset = SkIRect::MakeXYWH(x, 0, currSubsetWidth,
+                        codec->getInfo().height());
+                SkCodec::Options options;
+                options.fSubset = &subset;
+
+                SkDEBUGCODE(SkCodec::Result result =)
+                codec->startScanlineDecode(info, &options, get_colors(&bitmap), &colorCount);
+                SkASSERT(SkCodec::kSuccess == result);
+
+                SkDEBUGCODE(bool success =) codec->skipScanlines(y);
+                SkASSERT(success);
+
+                SkDEBUGCODE(uint32_t lines =) codec->getScanlines(bitmap.getPixels(),
+                        currSubsetHeight, bitmap.rowBytes());
+                SkASSERT(currSubsetHeight == lines);
             }
         }
     }
diff --git a/bench/subset/SubsetTranslateBench.h b/bench/subset/SubsetTranslateBench.h
index 298732c851..49682d37c7 100644
--- a/bench/subset/SubsetTranslateBench.h
+++ b/bench/subset/SubsetTranslateBench.h
@@ -23,8 +23,7 @@ public:
     SubsetTranslateBench(const SkString& path,
                          SkColorType colorType,
                          uint32_t subsetWidth,
-                         uint32_t subsetHeight,
-                         bool useCodec);
+                         uint32_t subsetHeight);
 
 protected:
     const char* onGetName() override;
@@ -36,7 +35,6 @@ private:
     SkColorType                   fColorType;
     const uint32_t                fSubsetWidth;
     const uint32_t                fSubsetHeight;
-    const bool                    fUseCodec;
     SkAutoTDelete<SkMemoryStream> fStream;
     typedef Benchmark INHERITED;
 };
diff --git a/bench/subset/SubsetZoomBench.cpp b/bench/subset/SubsetZoomBench.cpp
index f17a97c26b..1712595d7a 100644
--- a/bench/subset/SubsetZoomBench.cpp
+++ b/bench/subset/SubsetZoomBench.cpp
@@ -24,12 +24,10 @@
 SubsetZoomBench::SubsetZoomBench(const SkString& path,
                                  SkColorType colorType,
                                  uint32_t subsetWidth,
-                                 uint32_t subsetHeight,
-                                 bool useCodec)
+                                 uint32_t subsetHeight)
     : fColorType(colorType)
     , fSubsetWidth(subsetWidth)
     , fSubsetHeight(subsetHeight)
-    , fUseCodec(useCodec)
 {
     // Parse the filename
     SkString baseName = SkOSPath::Basename(path.c_str());
@@ -37,7 +35,7 @@ SubsetZoomBench::SubsetZoomBench(const SkString& path,
     // Choose an informative color name
     const char* colorName = color_type_to_str(fColorType);
 
-    fName.printf("%sSubsetZoom_%dx%d_%s_%s", fUseCodec ? "Codec" : "Image", fSubsetWidth,
+    fName.printf("CodecSubsetZoom_%dx%d_%s_%s", fSubsetWidth,
             fSubsetHeight, baseName.c_str(), colorName);
     
     // Perform the decode setup
@@ -58,71 +56,46 @@ void SubsetZoomBench::onDraw(int n, SkCanvas* canvas) {
     // used, it will be initialized by the codec.
     int colorCount;
     SkPMColor colors[256];
-    if (fUseCodec) {
-        for (int count = 0; count < n; count++) {
-            SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(fStream->duplicate()));
-            SkASSERT(SkCodec::kOutOfOrder_SkScanlineOrder != codec->getScanlineOrder());
-            const SkImageInfo info = codec->getInfo().makeColorType(fColorType);
-
-            const int centerX = info.width() / 2;
-            const int centerY = info.height() / 2;
-            int w = fSubsetWidth;
-            int h = fSubsetHeight;
-            do {
-                const int subsetStartX = SkTMax(0, centerX - w / 2);
-                const int subsetStartY = SkTMax(0, centerY - h / 2);
-                const int subsetWidth = SkTMin(w, info.width() - subsetStartX);
-                const int subsetHeight = SkTMin(h, info.height() - subsetStartY);
-
-                // The scanline decoder will handle subsetting in the x-dimension.
-                SkIRect subset = SkIRect::MakeXYWH(subsetStartX, 0, subsetWidth,
-                        codec->getInfo().height());
-                SkCodec::Options options;
-                options.fSubset = &subset;
-
-                SkDEBUGCODE(SkCodec::Result result = )
-                codec->startScanlineDecode(info, &options, colors, &colorCount);
-                SkASSERT(SkCodec::kSuccess == result);
-
-                // Note that if we subsetted and scaled in a single step, we could use the
-                // same bitmap - as is often done in actual use cases.
-                SkBitmap bitmap;
-                SkImageInfo subsetInfo = info.makeWH(subsetWidth, subsetHeight);
-                alloc_pixels(&bitmap, subsetInfo, colors, colorCount);
-
-                SkDEBUGCODE(bool success = ) codec->skipScanlines(subsetStartY);
-                SkASSERT(success);
-
-                SkDEBUGCODE(int lines = ) codec->getScanlines(bitmap.getPixels(),
-                        subsetHeight, bitmap.rowBytes());
-                SkASSERT(subsetHeight == lines);
-
-                w <<= 1;
-                h <<= 1;
-            } while (w < 2 * info.width() || h < 2 * info.height());
-        }
-    } else {
-        for (int count = 0; count < n; count++) {
-            int width, height;
-            SkAutoTDelete<SkImageDecoder> decoder(SkImageDecoder::Factory(fStream));
-            SkAssertResult(decoder->buildTileIndex(fStream->duplicate(), &width, &height));
-
-            const int centerX = width / 2;
-            const int centerY = height / 2;
-            int w = fSubsetWidth;
-            int h = fSubsetHeight;
-            do {
-                const int subsetStartX = SkTMax(0, centerX - w / 2);
-                const int subsetStartY = SkTMax(0, centerY - h / 2);
-                const int subsetWidth = SkTMin(w, width - subsetStartX);
-                const int subsetHeight = SkTMin(h, height - subsetStartY);
-                SkBitmap bitmap;
-                SkIRect rect = SkIRect::MakeXYWH(subsetStartX, subsetStartY, subsetWidth,
-                        subsetHeight);
-                SkAssertResult(decoder->decodeSubset(&bitmap, rect, fColorType));
-                w <<= 1;
-                h <<= 1;
-            } while (w < 2 * width || h < 2 * height);
-        }
+    for (int count = 0; count < n; count++) {
+        SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(fStream->duplicate()));
+        SkASSERT(SkCodec::kOutOfOrder_SkScanlineOrder != codec->getScanlineOrder());
+        const SkImageInfo info = codec->getInfo().makeColorType(fColorType);
+
+        const int centerX = info.width() / 2;
+        const int centerY = info.height() / 2;
+        int w = fSubsetWidth;
+        int h = fSubsetHeight;
+        do {
+            const int subsetStartX = SkTMax(0, centerX - w / 2);
+            const int subsetStartY = SkTMax(0, centerY - h / 2);
+            const int subsetWidth = SkTMin(w, info.width() - subsetStartX);
+            const int subsetHeight = SkTMin(h, info.height() - subsetStartY);
+
+            // The scanline decoder will handle subsetting in the x-dimension.
+            SkIRect subset = SkIRect::MakeXYWH(subsetStartX, 0, subsetWidth,
+                    codec->getInfo().height());
+            SkCodec::Options options;
+            options.fSubset = &subset;
+
+            SkDEBUGCODE(SkCodec::Result result = )
+            codec->startScanlineDecode(info, &options, colors, &colorCount);
+            SkASSERT(SkCodec::kSuccess == result);
+
+            // Note that if we subsetted and scaled in a single step, we could use the
+            // same bitmap - as is often done in actual use cases.
+            SkBitmap bitmap;
+            SkImageInfo subsetInfo = info.makeWH(subsetWidth, subsetHeight);
+            alloc_pixels(&bitmap, subsetInfo, colors, colorCount);
+
+            SkDEBUGCODE(bool success = ) codec->skipScanlines(subsetStartY);
+            SkASSERT(success);
+
+            SkDEBUGCODE(int lines = ) codec->getScanlines(bitmap.getPixels(),
+                    subsetHeight, bitmap.rowBytes());
+            SkASSERT(subsetHeight == lines);
+
+            w <<= 1;
+            h <<= 1;
+        } while (w < 2 * info.width() || h < 2 * info.height());
     }
 }
diff --git a/bench/subset/SubsetZoomBench.h b/bench/subset/SubsetZoomBench.h
index 7fba4af940..96e2eb1fc1 100644
--- a/bench/subset/SubsetZoomBench.h
+++ b/bench/subset/SubsetZoomBench.h
@@ -23,8 +23,7 @@ public:
     SubsetZoomBench(const SkString& path,
                     SkColorType colorType,
                     uint32_t subsetWidth,
-                    uint32_t subsetHeight,
-                    bool useCodec);
+                    uint32_t subsetHeight);
 
 protected:
     const char* onGetName() override;
@@ -36,7 +35,6 @@ private:
     SkColorType                   fColorType;
     const uint32_t                fSubsetWidth;
     const uint32_t                fSubsetHeight;
-    const bool                    fUseCodec;
     SkAutoTDelete<SkMemoryStream> fStream;
     typedef Benchmark INHERITED;
 };