GN: Define SK_HAS_... in all Skia-private code, not just libskia.

BUILD.gn

 # Copyright 2016 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 declare_args() {
 }
 
 skia_public_includes = [
   "include/android",
@@ skipping 38 matching lines @@
     "src/lazy",
     "src/opts",
     "src/pathops",
     "src/pdf",
     "src/ports",
     "src/sfnt",
     "src/utils",
     "third_party/etc1",
     "third_party/ktx",
   ]
+
+  defines = [
+    "SK_HAS_GIF_LIBRARY",
+    "SK_HAS_JPEG_LIBRARY",
+    "SK_HAS_PNG_LIBRARY",
+    "SK_HAS_WEBP_LIBRARY",
+  ]
 }
 
 # Any code that's linked into Skia-the-library should use this config via += skia_library_configs.
 config("skia_library") {
   visibility = [ ":*" ]
   defines = [ "SKIA_IMPLEMENTATION=1" ]
 }
 
 skia_library_configs = [
   ":skia_public",
@@ skipping 85 matching lines @@
     ":opts_sse41",
     ":opts_ssse3",
     "//third_party/expat",
     "//third_party/giflib",
     "//third_party/libjpeg_turbo",
     "//third_party/libpng",
     "//third_party/libwebp",
     "//third_party/zlib",
   ]
 
-  defines = [
-    "SK_HAS_GIF_LIBRARY",
-    "SK_HAS_JPEG_LIBRARY",
-    "SK_HAS_PNG_LIBRARY",
-    "SK_HAS_WEBP_LIBRARY",
-  ]
-
   libs = [ "pthread" ]
 
   sources = []
   sources += core_gypi.sources
   sources += effects_gypi.sources
   sources += gpu_gypi.skgpu_sources
   sources += opts_gypi.sse2_sources
   sources += pdf_gypi.sources
   sources += utils_gypi.sources
   sources += [
@@ skipping 291 matching lines @@
       ":flags",
       ":gm",
       ":gpu_tool_utils",
       ":skia",
       ":tool_utils",
       "//third_party/jsoncpp",
     ]
     testonly = true
   }
 }