Revert "unguard SkFooEncoder.cpp"

This reverts commit 32c32b9a6caac9edc4a244713d31d63b81619231.

Reason for revert: <INSERT REASONING HERE>

Original change's description:
> unguard SkFooEncoder.cpp
> 
> We used to define SkFooEncoder::Encode() either
> here or as failing stubs in SkImageEncoder.cpp.
> 
> Now that we're not defining them in SkImageEncoder.cpp,
> we can lift these guards here.
> 
> Change-Id: Id916811225450e4c3a84f1e7f38ae510be1d6268
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/214004
> Reviewed-by: Leon Scroggins <scroggo@google.com>
> Commit-Queue: Mike Klein <mtklein@google.com>

TBR=mtklein@google.com,scroggo@google.com

Change-Id: I089a21d2fd4928969d956e47981a36efa71d9378
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/214101
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
diff --git a/src/images/SkJpegEncoder.cpp b/src/images/SkJpegEncoder.cpp
index 0c3fd76..2b0afb8 100644
--- a/src/images/SkJpegEncoder.cpp
+++ b/src/images/SkJpegEncoder.cpp
@@ -7,6 +7,8 @@
 
 #include "src/images/SkImageEncoderPriv.h"
 
+#ifdef SK_HAS_JPEG_LIBRARY
+
 #include "include/core/SkStream.h"
 #include "include/encode/SkJpegEncoder.h"
 #include "include/private/SkColorData.h"
@@ -239,3 +241,5 @@
     auto encoder = SkJpegEncoder::Make(dst, src, options);
     return encoder.get() && encoder->encodeRows(src.height());
 }
+
+#endif