Remove superfluous error messages from nanobench

tools/SkBitmapRegionDecoderInterface.cpp

Index: tools/SkBitmapRegionDecoderInterface.cpp
diff --git a/tools/SkBitmapRegionDecoderInterface.cpp b/tools/SkBitmapRegionDecoderInterface.cpp
index 5c769d676e4377da9ee1f34e1aeb06d76c48c9f0..d6afca72046683c537d0850a063792fa9c5542b9 100644
--- a/tools/SkBitmapRegionDecoderInterface.cpp
+++ b/tools/SkBitmapRegionDecoderInterface.cpp
@@ -18,11 +18,9 @@ SkBitmapRegionDecoderInterface* SkBitmapRegionDecoderInterface::CreateBitmapRegi
             SkImageDecoder* decoder = SkImageDecoder::Factory(stream);
             int width, height;
             if (nullptr == decoder) {
-                SkDebugf("Error: Could not create image decoder.\n");
                 return nullptr;
             }
             if (!decoder->buildTileIndex(stream, &width, &height)) {
-                SkDebugf("Error: Could not build tile index.\n");
                 delete decoder;
                 return nullptr;
             }
@@ -31,7 +29,6 @@ SkBitmapRegionDecoderInterface* SkBitmapRegionDecoderInterface::CreateBitmapRegi
         case kCanvas_Strategy: {
             SkCodec* decoder = SkCodec::NewFromStream(stream);
             if (nullptr == decoder) {
-                SkDebugf("Error: Failed to create decoder.\n");
                 return nullptr;
             }
             switch (decoder->getScanlineOrder()) {
@@ -39,7 +36,6 @@ SkBitmapRegionDecoderInterface* SkBitmapRegionDecoderInterface::CreateBitmapRegi
                 case SkCodec::kNone_SkScanlineOrder:
                     break;
                 default:
-                    SkDebugf("Error: Scanline ordering not supported.\n");
                     return nullptr;
             }
             return new SkBitmapRegionCanvas(decoder);