Force U.S. English keyboard layout for TextfieldTest.KeysWithModifiersTest

ui/events/BUILD.gn

Index: ui/events/BUILD.gn
diff --git a/ui/events/BUILD.gn b/ui/events/BUILD.gn
index b6d5cd40f8abe54d51465d29eec5bd325cac265a..ceb4acba3fbd8f94c25abcc7c9a40f1107825dbc 100644
--- a/ui/events/BUILD.gn
+++ b/ui/events/BUILD.gn
@@ -276,6 +276,10 @@ static_library("test_support") {
     "test/event_generator.h",
     "test/events_test_utils.cc",
     "test/events_test_utils.h",
+    "test/keyboard_layout.cc",
+    "test/keyboard_layout.h",
+    "test/keyboard_layout_mac.cc",
+    "test/keyboard_layout_win.cc",
     "test/motion_event_test_utils.cc",
     "test/motion_event_test_utils.h",
     "test/platform_event_source_test_api.cc",