GN: ft and fc as optionals

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_enable_tools = !is_fuchsia && !is_component_build
 
   skia_use_expat = true
+  skia_use_fontconfig = is_linux
+  skia_use_freetype = is_android || is_linux
   skia_use_giflib = !is_fuchsia
   skia_use_libjpeg_turbo = true
   skia_use_libpng = true
   skia_use_libwebp = !is_fuchsia
   skia_use_sfntly = !is_fuchsia
   skia_use_zlib = true
 }
 
 skia_public_includes = [
   "include/android",
@@ skipping 219 matching lines @@
                              "*",
                              [
                                "public_defines",
                                "deps",
                                "sources",
                              ])
     }
   }
 }
 
+optional("fontmgr_fontconfig") {
+  enabled = skia_use_freetype && skia_use_fontconfig
+  public_defines = []
+
+  deps = [
+    "//third_party:fontconfig",
+    "//third_party/freetype2",
+  ]
+  sources = [
+    "src/ports/SkFontConfigInterface_direct.cpp",
+    "src/ports/SkFontConfigInterface_direct_factory.cpp",
+    "src/ports/SkFontMgr_FontConfigInterface.cpp",
+    "src/ports/SkFontMgr_fontconfig.cpp",
+    "src/ports/SkFontMgr_fontconfig_factory.cpp",
+  ]
+}
+
 optional("gif") {
   enabled = skia_use_giflib
   public_defines = [ "SK_HAS_GIF_LIBRARY" ]
 
   deps = [
     "//third_party/giflib",
   ]
   sources = [
     "src/codec/SkGifCodec.cpp",
   ]
@@ skipping 37 matching lines @@
   deps = [
     "//third_party/libpng",
   ]
   sources = [
     "src/codec/SkIcoCodec.cpp",
     "src/codec/SkPngCodec.cpp",
     "src/images/SkPNGImageEncoder.cpp",
   ]
 }
 
+optional("typeface_freetype") {
+  enabled = skia_use_freetype
+  public_defines = []
+
+  deps = [
+    "//third_party/freetype2",
+  ]
+  sources = [
+    "src/ports/SkFontHost_FreeType.cpp",
+    "src/ports/SkFontHost_FreeType_common.cpp",
+  ]
+}
+
 optional("webp") {
   enabled = skia_use_libwebp
   public_defines = [ "SK_HAS_WEBP_LIBRARY" ]
 
   deps = [
     "//third_party/libwebp",
   ]
   sources = [
     "src/codec/SkWebpAdapterCodec.cpp",
     "src/codec/SkWebpCodec.cpp",
@@ skipping 18 matching lines @@
 component("skia") {
   public_configs = [ ":skia_public" ]
   configs += skia_library_configs
 
   deps = [
     ":arm64",
     ":armv7",
     ":avx",
     ":crc32",
     ":dsp",
+    ":fontmgr_fontconfig",
     ":gif",
     ":jpeg",
     ":none",
     ":pdf",
     ":png",
     ":sse2",
     ":sse41",
     ":sse42",
     ":ssse3",
+    ":typeface_freetype",
     ":webp",
     ":xml",
   ]
 
   sources = []
   sources += core_gypi.sources
   sources += effects_gypi.sources
   sources += gpu_gypi.skgpu_sources
   sources += utils_gypi.sources
   sources += [
@@ skipping 56 matching lines @@
       "src/ports/SkOSFile_posix.cpp",
       "src/ports/SkTLS_pthread.cpp",
       "src/xps/SkDocument_XPS_None.cpp",
     ]
   }
 
   if (is_android) {
     deps += [
       "//third_party/cpu-features",
       "//third_party/expat",
-      "//third_party/freetype2",
     ]
     sources += [
       "src/gpu/gl/android/GrGLCreateNativeInterface_android.cpp",
       "src/ports/SkDebug_android.cpp",
-      "src/ports/SkFontHost_FreeType.cpp",
-      "src/ports/SkFontHost_FreeType_common.cpp",
       "src/ports/SkFontMgr_android.cpp",
       "src/ports/SkFontMgr_android_factory.cpp",
       "src/ports/SkFontMgr_android_parser.cpp",
     ]
     libs += [
       "EGL",
       "GLESv2",
       "log",
     ]
   }
 
   if (is_linux) {
-    deps += [
-      "third_party:fontconfig",
-      "//third_party/freetype2",
-    ]
     libs += [
       "GL",
       "GLU",
       "X11",
     ]
     sources += [
       "src/gpu/gl/glx/GrGLCreateNativeInterface_glx.cpp",
       "src/ports/SkDebug_stdio.cpp",
-      "src/ports/SkFontConfigInterface_direct.cpp",
-      "src/ports/SkFontConfigInterface_direct_factory.cpp",
-      "src/ports/SkFontHost_FreeType.cpp",
-      "src/ports/SkFontHost_FreeType_common.cpp",
-      "src/ports/SkFontMgr_FontConfigInterface.cpp",
-      "src/ports/SkFontMgr_fontconfig.cpp",
-      "src/ports/SkFontMgr_fontconfig_factory.cpp",
     ]
   }
 
   if (is_mac) {
     sources += [
       "src/gpu/gl/mac/GrGLCreateNativeInterface_mac.cpp",
       "src/ports/SkDebug_stdio.cpp",
       "src/ports/SkFontHost_mac.cpp",
       "src/ports/SkImageEncoder_CG.cpp",
       "src/ports/SkImageGeneratorCG.cpp",
@@ skipping 296 matching lines @@
       "tools/SkShaper_harfbuzz.cpp",
       "tools/using_skia_and_harfbuzz.cpp",
     ]
     deps = [
       ":skia",
       "//third_party/harfbuzz",
     ]
     testonly = true
   }
 }