Create FP16 LUTs when needed

ui/gfx/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 import("//testing/libfuzzer/fuzzer_test.gni")
 
 if (is_android) {
   import("//build/config/android/config.gni")
@@ skipping 73 matching lines @@
     "font_render_params.cc",
     "font_render_params.h",
     "font_render_params_android.cc",
     "font_render_params_linux.cc",
     "font_render_params_mac.cc",
     "font_render_params_win.cc",
     "gdi_util.cc",
     "gdi_util.h",
     "gfx_paths.cc",
     "gfx_paths.h",
+    "half_float.cc",
+    "half_float.h",
     "icc_profile.cc",
     "icc_profile.h",
     "icc_profile_mac.mm",
     "icc_profile_win.cc",
     "icc_profile_x11.cc",
     "icon_util.cc",
     "icon_util.h",
     "image/image.cc",
     "image/image.h",
     "image/image_family.cc",
@@ skipping 328 matching lines @@
 
   defines = [ "GFX_IMPLEMENTATION" ]
 
   public_deps = [
     ":gfx_export",
     "//base",
     "//skia",
   ]
 }
 
+# Depend on this to use half_float.h without pulling in all of gfx.
+source_set("half_float") {
+  sources = [
+    "half_float.h",
+  ]
+
+  defines = [ "GFX_IMPLEMENTATION" ]
+
+  public_deps = [
+    ":gfx_export",
+    "//base",
+  ]
+}
+
 # Depend on this to use native_widget_types.h without pulling in all of gfx.
 source_set("native_widget_types") {
   public = [
     "native_widget_types.h",
   ]
 
   public_deps = [
     "//base",
   ]
 }
@@ skipping 171 matching lines @@
       "geometry/matrix3_unittest.cc",
       "geometry/point3_unittest.cc",
       "geometry/point_unittest.cc",
       "geometry/quad_unittest.cc",
       "geometry/rect_unittest.cc",
       "geometry/safe_integer_conversions_unittest.cc",
       "geometry/scroll_offset_unittest.cc",
       "geometry/size_unittest.cc",
       "geometry/vector2d_unittest.cc",
       "geometry/vector3d_unittest.cc",
+      "half_float_unittest.cc",
       "icc_profile_unittest.cc",
       "image/image_mac_unittest.mm",
       "image/image_util_unittest.cc",
       "mac/coordinate_conversion_unittest.mm",
       "mojo/struct_traits_unittest.cc",
       "nine_image_painter_unittest.cc",
       "path_mac_unittest.mm",
       "platform_font_mac_unittest.mm",
       "range/range_mac_unittest.mm",
       "range/range_unittest.cc",
@@ skipping 101 matching lines @@
 
 fuzzer_test("color_transform_fuzztest") {
   sources = [
     "color_transform_fuzzer.cc",
   ]
   deps = [
     ":gfx",
   ]
   libfuzzer_options = [ "max_len=1024" ]
 }