Replace (unused) FontPlatformData.* with harfbuzz variants.

sky/engine/platform/BUILD.gn

Index: sky/engine/platform/BUILD.gn
diff --git a/sky/engine/platform/BUILD.gn b/sky/engine/platform/BUILD.gn
index 261912b387091764d170113b5d514a51a492aae7..160b8bc4e8809da92a7ca25862c41e9f796fee8c 100644
--- a/sky/engine/platform/BUILD.gn
+++ b/sky/engine/platform/BUILD.gn
@@ -195,11 +195,8 @@ component("platform") {
     "fonts/GlyphPageTreeNode.cpp",
     "fonts/GlyphPageTreeNode.h",
     "fonts/harfbuzz/FontHarfBuzz.cpp",
-    "fonts/harfbuzz/FontPlatformDataHarfBuzz.cpp",
-    "fonts/harfbuzz/FontPlatformDataHarfBuzz.h",
     "fonts/harfbuzz/HarfBuzzFace.cpp",
     "fonts/harfbuzz/HarfBuzzFace.h",
-    "fonts/harfbuzz/HarfBuzzFaceCoreText.cpp",
     "fonts/harfbuzz/HarfBuzzFaceSkia.cpp",
     "fonts/harfbuzz/HarfBuzzShaper.cpp",
     "fonts/harfbuzz/HarfBuzzShaper.h",
@@ -696,14 +693,6 @@ component("platform") {
     "//v8",
   ]
 
-  # FIXME(sky): Can sky use this stuff? Why mac only?
-  sources -= [
-    # FIXME: We will eventually compile this too, but for now it's
-    # only used on mac.
-    "fonts/FontPlatformData.cpp",
-    "fonts/harfbuzz/HarfBuzzFaceCoreText.cpp",
-  ]
-
   if (is_android) {
     # Add in some Linux files also shared with Android.
     set_sources_assignment_filter([])