Clean up deprecated sources assignment filter in //chrome/utility

Remove deprecated_default_sources_assignment_filter and replace
it with explicit is_win, is_mac, etc. sections.

Bug: 1018739
Change-Id: I8972870aab6d8bd87c8b4233c0f53240bc904aa5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2445481
Commit-Queue: Scott Violet <sky@chromium.org>
Auto-Submit: Sylvain Defresne <sdefresne@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#814469}

chrome/utility/BUILD.gn

@@ -10,13 +10,6 @@ import("//chromeos/assistant/assistant.gni")
 import("//extensions/buildflags/buildflags.gni")
 import("//printing/buildflags/buildflags.gni")
 
-# This file depends on the legacy global sources assignment filter. It should
-# be converted to check target platform before assigning source files to the
-# sources variable. Remove this import and set_sources_assignment_filter call
-# when the file has been converted. See https://crbug.com/1018739 for details.
-import("//build/config/deprecated_default_sources_assignment_filter.gni")
-set_sources_assignment_filter(deprecated_default_sources_assignment_filter)
-
 static_library("utility") {
   sources = [
     "browser_exposed_utility_interfaces.cc",
@@ -82,33 +75,40 @@ static_library("utility") {
       "importer/bookmark_html_reader.h",
       "importer/bookmarks_file_importer.cc",
       "importer/bookmarks_file_importer.h",
-      "importer/edge_database_reader_win.cc",
-      "importer/edge_database_reader_win.h",
-      "importer/edge_importer_win.cc",
-      "importer/edge_importer_win.h",
       "importer/external_process_importer_bridge.cc",
       "importer/external_process_importer_bridge.h",
       "importer/favicon_reencode.cc",
       "importer/favicon_reencode.h",
       "importer/firefox_importer.cc",
       "importer/firefox_importer.h",
-      "importer/ie_importer_win.cc",
-      "importer/ie_importer_win.h",
       "importer/importer.cc",
       "importer/importer.h",
       "importer/importer_creator.cc",
       "importer/importer_creator.h",
       "importer/nss_decryptor.cc",
       "importer/nss_decryptor.h",
-      "importer/nss_decryptor_mac.h",
-      "importer/nss_decryptor_mac.mm",
-      "importer/nss_decryptor_win.cc",
-      "importer/nss_decryptor_win.h",
       "importer/profile_import_impl.cc",
       "importer/profile_import_impl.h",
-      "importer/safari_importer.h",
-      "importer/safari_importer.mm",
     ]
+    if (is_mac) {
+      sources += [
+        "importer/nss_decryptor_mac.h",
+        "importer/nss_decryptor_mac.mm",
+        "importer/safari_importer.h",
+        "importer/safari_importer.mm",
+      ]
+    } else if (is_win) {
+      sources += [
+        "importer/edge_database_reader_win.cc",
+        "importer/edge_database_reader_win.h",
+        "importer/edge_importer_win.cc",
+        "importer/edge_importer_win.h",
+        "importer/ie_importer_win.cc",
+        "importer/ie_importer_win.h",
+        "importer/nss_decryptor_win.cc",
+        "importer/nss_decryptor_win.h",
+      ]
+    }
     deps += [
       "//chrome/common:mojo_bindings",
       "//chrome/common/importer:interfaces",
@@ -120,17 +120,23 @@ static_library("utility") {
 
   if (enable_extensions) {
     sources += [
-      "image_writer/disk_unmounter_mac.cc",
-      "image_writer/disk_unmounter_mac.h",
       "image_writer/error_message_strings.cc",
       "image_writer/error_message_strings.h",
       "image_writer/image_writer.cc",
       "image_writer/image_writer.h",
       "image_writer/image_writer_handler.cc",
       "image_writer/image_writer_handler.h",
-      "image_writer/image_writer_mac.cc",
-      "image_writer/image_writer_win.cc",
     ]
+    if (is_mac) {
+      sources += [
+        "image_writer/disk_unmounter_mac.cc",
+        "image_writer/disk_unmounter_mac.h",
+        "image_writer/image_writer_mac.cc",
+      ]
+    } else if (is_win) {
+      sources += [ "image_writer/image_writer_win.cc" ]
+    }
+
     deps += [
       "//chrome/common/extensions/api",
       "//chrome/services/removable_storage_writer:lib",