Add timing SkCodec to nanobench.

CodecBench:
Add new class for timing using SkCodec.

DecodingBench:
Include creating a decoder inside the loop. This is to have a better
comparison against SkCodec. SkCodec's factory function does not
necessarily read the same amount as SkImageDecoder's, so in order to
have a meaningful comparison, read the entire stream from the
beginning. Also for comparison, create a new SkStream from the
SkData each time.
Add a debugging check to make sure we have an SkImageDecoder.
Add include guards.

nanobench.cpp:
Decode using SkCodec.
When decoding using SkImageDecoder, exclude benches where we decoded
to a different color type than requested. SkImageDecoder may decide to
decode to a different type, in which case the name is misleading.

TODOs:
Now that we ignore color types that do not match the desired
color type, we should add Index8. This also means calling the more
complex version of getPixels so CodecBench can support kIndex8.

BUG=skia:3257

Review URL: https://codereview.chromium.org/1044363002

1 files changed, 47 insertions, 2 deletions

diff --git a/bench/nanobench.cpp b/bench/nanobench.cpp
index 07600ef3a4..a627b50a3a 100644
--- a/bench/nanobench.cpp
+++ b/bench/nanobench.cpp
@@ -10,6 +10,7 @@
 #include "nanobench.h"
 
 #include "Benchmark.h"
+#include "CodecBench.h"
 #include "CrashHandler.h"
 #include "DecodingBench.h"
 #include "DecodingSubsetBench.h"
@@ -23,6 +24,7 @@
 
 #include "SkBBoxHierarchy.h"
 #include "SkCanvas.h"
+#include "SkCodec.h"
 #include "SkCommonFlags.h"
 #include "SkData.h"
 #include "SkForceLinking.h"
@@ -485,6 +487,7 @@ public:
                       , fCurrentScale(0)
                       , fCurrentSKP(0)
                       , fCurrentUseMPD(0)
+                      , fCurrentCodec(0)
                       , fCurrentImage(0)
                       , fCurrentSubsetImage(0)
                       , fCurrentColorType(0)
@@ -632,16 +635,57 @@ public:
             fCurrentScale++;
         }
 
+        for (; fCurrentCodec < fImages.count(); fCurrentCodec++) {
+            const SkString& path = fImages[fCurrentCodec];
+            SkAutoTUnref<SkData> encoded(SkData::NewFromFileName(path.c_str()));
+            SkAutoTDelete<SkCodec> codec(SkCodec::NewFromData(encoded));
+            SkASSERT(codec);
+            if (!codec) {
+                // Nothing to time.
+                continue;
+            }
+            while (fCurrentColorType < fColorTypes.count()) {
+                SkColorType colorType = fColorTypes[fCurrentColorType];
+                fCurrentColorType++;
+                // Make sure we can decode to this color type.
+                SkBitmap bitmap;
+                SkImageInfo info = codec->getInfo().makeColorType(colorType);
+                bitmap.allocPixels(info);
+                const SkImageGenerator::Result result = codec->getPixels(
+                        bitmap.info(), bitmap.getPixels(), bitmap.rowBytes());
+                switch (result) {
+                    case SkImageGenerator::kSuccess:
+                    case SkImageGenerator::kIncompleteInput:
+                        return new CodecBench(SkOSPath::Basename(path.c_str()),
+                                encoded, colorType);
+                    case SkImageGenerator::kInvalidConversion:
+                        // This is okay. Not all conversions are valid.
+                        break;
+                    case SkImageGenerator::kCouldNotRewind:
+                        // FIXME: This is due to a bug in some implementations
+                        // of SkCodec. All should support rewinding.
+                        break;
+                    default:
+                        // This represents some sort of failure.
+                        SkASSERT(false);
+                        break;
+                }
+            }
+            fCurrentColorType = 0;
+        }
+
         // Run the DecodingBenches
         while (fCurrentImage < fImages.count()) {
             while (fCurrentColorType < fColorTypes.count()) {
                 const SkString& path = fImages[fCurrentImage];
                 SkColorType colorType = fColorTypes[fCurrentColorType];
                 fCurrentColorType++;
-                // Check if the image decodes before creating the benchmark
+                // Check if the image decodes to the right color type
+                // before creating the benchmark
                 SkBitmap bitmap;
                 if (SkImageDecoder::DecodeFile(path.c_str(), &bitmap,
-                        colorType, SkImageDecoder::kDecodePixels_Mode)) {
+                        colorType, SkImageDecoder::kDecodePixels_Mode)
+                        && bitmap.colorType() == colorType) {
                     return new DecodingBench(path, colorType);
                 }
             }
@@ -741,6 +785,7 @@ private:
     int fCurrentScale;
     int fCurrentSKP;
     int fCurrentUseMPD;
+    int fCurrentCodec;
     int fCurrentImage;
     int fCurrentSubsetImage;
     int fCurrentColorType;