Individually enable and disable SkCodecs

src/codec/SkCodec.cpp

Index: src/codec/SkCodec.cpp
diff --git a/src/codec/SkCodec.cpp b/src/codec/SkCodec.cpp
index bb7b26529b9af8fe7c106818e5514c47617cdf76..b53e9268133e60b922f425607a06bb2fdb0b5c73 100644
--- a/src/codec/SkCodec.cpp
+++ b/src/codec/SkCodec.cpp
@@ -5,20 +5,35 @@
  * found in the LICENSE file.
  */
 
-#include "SkBmpCodec.h"
 #include "SkCodec.h"
 #include "SkCodecPriv.h"
 #include "SkData.h"
+#include "SkStream.h"
+
+#ifdef SK_CODEC_DECODES_BMP

[mtklein, 2016/02/16 23:16:01]

You might not need to guard all these headers?  IIRC, only SkGifCodec.h had
trouble with gif_lib.h wasn't available (and I think we could fix that).

[msarett, 2016/02/17 14:34:54]

Done.  Was able to get rid of some but not all of these.

+#include "SkBmpCodec.h"
+#endif
+#ifdef SK_CODEC_DECODES_GIF
 #include "SkGifCodec.h"
+#endif
+#ifdef SK_CODEC_DECODES_ICO
 #include "SkIcoCodec.h"
+#endif
+#ifdef SK_CODEC_DECODES_JPEG
 #include "SkJpegCodec.h"
+#endif
+#ifdef SK_CODEC_DECODES_PNG
 #include "SkPngCodec.h"
+#endif
 #ifdef SK_CODEC_DECODES_RAW
 #include "SkRawCodec.h"
 #endif
-#include "SkStream.h"
+#ifdef SK_CODEC_DECODES_WBMP
 #include "SkWbmpCodec.h"
+#endif
+#ifdef SK_CODEC_DECODES_WEBP
 #include "SkWebpCodec.h"
+#endif
 
 struct DecoderProc {
     bool (*IsFormat)(const void*, size_t);
@@ -26,16 +41,32 @@ struct DecoderProc {
 };
 
 static const DecoderProc gDecoderProcs[] = {
+#ifdef SK_CODEC_DECODES_JPEG
     { SkJpegCodec::IsJpeg, SkJpegCodec::NewFromStream },
+#endif
+#ifdef SK_CODEC_DECODES_WEBP
     { SkWebpCodec::IsWebp, SkWebpCodec::NewFromStream },
+#endif
+#ifdef SK_CODEC_DECODES_GIF
     { SkGifCodec::IsGif, SkGifCodec::NewFromStream },
+#endif
+#ifdef SK_CODEC_DECODES_ICO
     { SkIcoCodec::IsIco, SkIcoCodec::NewFromStream },
+#endif
+#ifdef SK_CODEC_DECODES_BMP
     { SkBmpCodec::IsBmp, SkBmpCodec::NewFromStream },
+#endif
+#ifdef SK_CODEC_DECODES_WBMP
     { SkWbmpCodec::IsWbmp, SkWbmpCodec::NewFromStream }
+#endif
 };
 
 size_t SkCodec::MinBufferedBytesNeeded() {
+#ifdef SK_CODEC_DECODES_WEBP
     return WEBP_VP8_HEADER_SIZE;
+#else
+    return 30;
+#endif
 }
 
 SkCodec* SkCodec::NewFromStream(SkStream* stream,
@@ -77,9 +108,12 @@ SkCodec* SkCodec::NewFromStream(SkStream* stream,
 
     // PNG is special, since we want to be able to supply an SkPngChunkReader.
     // But this code follows the same pattern as the loop.
+#ifdef SK_CODEC_DECODES_PNG
     if (SkPngCodec::IsPng(buffer, bytesRead)) {
         return SkPngCodec::NewFromStream(streamDeleter.detach(), chunkReader);
-    } else {
+    } else
+#endif
+    {
         for (DecoderProc proc : gDecoderProcs) {
             if (proc.IsFormat(buffer, bytesRead)) {
                 return proc.NewFromStream(streamDeleter.detach());