Remove legacy StartsWithASCII function.

ui/base/ime/chromeos/component_extension_ime_manager.cc

Index: ui/base/ime/chromeos/component_extension_ime_manager.cc
diff --git a/ui/base/ime/chromeos/component_extension_ime_manager.cc b/ui/base/ime/chromeos/component_extension_ime_manager.cc
index 0f3d95b0ee9b30c392e32b15e5faf6e52cc66453..69f1d88ef74e8e65d90b22b965375ac68809c761 100644
--- a/ui/base/ime/chromeos/component_extension_ime_manager.cc
+++ b/ui/base/ime/chromeos/component_extension_ime_manager.cc
@@ -65,12 +65,12 @@ const char* kLoginLayoutWhitelist[] = {
 int GetInputMethodCategory(const std::string& id) {
   const std::string engine_id =
       chromeos::extension_ime_util::GetComponentIDByInputMethodID(id);
-  if (base::StartsWithASCII(engine_id, "xkb:", true))
+  if (base::StartsWith(engine_id, "xkb:", base::CompareCase::SENSITIVE))
     return 0;
-  if (base::StartsWithASCII(engine_id, "vkd_", true))
+  if (base::StartsWith(engine_id, "vkd_", base::CompareCase::SENSITIVE))
     return 1;
   if (engine_id.find("-t-i0-") != std::string::npos &&
-      !base::StartsWithASCII(engine_id, "zh-", true)) {
+      !base::StartsWith(engine_id, "zh-", base::CompareCase::SENSITIVE)) {
     return 2;
   }
   return 3;