Reduce messages from libjpeg-turbo

src/codec/SkJpegDecoderMgr.cpp

Index: src/codec/SkJpegDecoderMgr.cpp
diff --git a/src/codec/SkJpegDecoderMgr.cpp b/src/codec/SkJpegDecoderMgr.cpp
index 9e79dda9585f0cfd62f9051d262b690537b7b5d6..cc44f3c42117cd1b285ee5651180f47bd2b602df 100644
--- a/src/codec/SkJpegDecoderMgr.cpp
+++ b/src/codec/SkJpegDecoderMgr.cpp
@@ -18,11 +18,8 @@ static void print_message(const j_common_ptr info, const char caller[]) {
 }
 
 /*
- * Reporting functions for libjpeg
+ * Reporting function for error and warning messages.
  */
-static void emit_message(j_common_ptr info, int) {

[msarett, 2015/11/10 15:26:35]

The default implementation of emit_message is much better than this.

It does not print "trace messages" which essentially are info messages and it
only prints the first warning (unless it a very serious warning).

Currently, we just print everything, which is why the output has been so
verbose.

-    print_message(info, "emit_message");
-}
 static void output_message(j_common_ptr info) {

[msarett, 2015/11/10 15:26:35]

By overriding output_message, we can use SkCodecPrintf, which we can turn on or
off.

The default turbo implementation of emit_message calls output_message when it
wants to print a message, so, even though we don't override emit_message, it
also uses SkCodecPrintf.

     print_message(info, "output_message");
 }
@@ -59,7 +56,6 @@ void JpegDecoderMgr::init() {
     jpeg_create_decompress(&fDInfo);
     fInit = true;
     fDInfo.src = &fSrcMgr;
-    fDInfo.err->emit_message = &emit_message;
     fDInfo.err->output_message = &output_message;
 }