Move platform/loader/*_test.cc to the loader:unit_tests target

Bug: 800764
Change-Id: Ib680b466d28ef036462f07720371380f2302bd1e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2290111
Auto-Submit: Fredrik Söderquist <fs@opera.com>
Commit-Queue: Mike West <mkwst@chromium.org>
Reviewed-by: Mike West <mkwst@chromium.org>
Cr-Commit-Position: refs/heads/master@{#787598}

third_party/blink/renderer/platform/BUILD.gn

@@ -1981,8 +1981,6 @@ jumbo_source_set("blink_platform_unittests_sources") {
     "image-decoders/webp/webp_image_decoder_test.cc",
     "json/json_parser_test.cc",
     "json/json_values_test.cc",
-    "loader/allowed_by_nosniff_test.cc",
-    "loader/cors/cors_test.cc",
     "mac/graphics_context_canvas_test.mm",
     "media/webaudiosourceprovider_impl_test.cc",
     "mediastream/media_stream_audio_processor_options_test.cc",

third_party/blink/renderer/platform/loader/BUILD.gn

@@ -149,6 +149,8 @@ jumbo_source_set("unit_tests") {
 
   # Source files for blink_platform_unittests.
   sources = [
+    "allowed_by_nosniff_test.cc",
+    "cors/cors_test.cc",
     "fetch/buffering_bytes_consumer_test.cc",
     "fetch/bytes_consumer_test.cc",
     "fetch/client_hints_preferences_test.cc",