experimental/tools/coreGraphicsPdf2png: fix

NOTRY=true
TBR=

Review-Url: https://codereview.chromium.org/1944403002

experimental/tools/coreGraphicsPdf2png.cpp

@@ -9,9 +9,12 @@
 
 #include "SkBitmap.h"
 #include "SkCGUtils.h"
+#include "SkForceLinking.h"
 #include "SkImageEncoder.h"
 #include "SkStream.h"
 
+__SK_FORCE_IMAGE_DECODER_LINKING;
+
 class StdOutWStream : public SkWStream {
 public:
     StdOutWStream() : fBytesWritten(0) {}

gyp/experimental.gyp

@@ -33,7 +33,7 @@
             'type': 'executable',
             'include_dirs': [ '../src/core', ],
             'sources': [ '../experimental/tools/coreGraphicsPdf2png.cpp', ],
-            'dependencies': [ 'skia_lib.gyp:skia_lib', ]
+            'dependencies': [ 'skia_lib.gyp:skia_lib', 'libpng.gyp:libpng', ],
           },
         ],
       },