IME for Mus: Use ui::InputMethodChromeOS to provide logic for ime driver.

chrome/browser/ui/BUILD.gn

Index: chrome/browser/ui/BUILD.gn
diff --git a/chrome/browser/ui/BUILD.gn b/chrome/browser/ui/BUILD.gn
index 7fa6560e9e84be3dd2e15bdd581ecf495b3832c3..c1310a31deb01b156d53ff4938af4a22a99e71c9 100644
--- a/chrome/browser/ui/BUILD.gn
+++ b/chrome/browser/ui/BUILD.gn
@@ -1889,8 +1889,14 @@ split_static_library("ui") {
       # apart from aura::Window, which is also not supported).
       if (!is_mac) {
         sources += [
-          "views/ime_driver_mus.cc",
-          "views/ime_driver_mus.h",
+          "views/ime_driver/ime_driver_mus.cc",
+          "views/ime_driver/ime_driver_mus.h",
+          "views/ime_driver/input_method_bridge_chromeos.cc",
+          "views/ime_driver/input_method_bridge_chromeos.h",
+          "views/ime_driver/noop_input_method.cc",
+          "views/ime_driver/noop_input_method.h",
+          "views/ime_driver/remote_text_input_client.cc",
+          "views/ime_driver/remote_text_input_client.h",
           "views/tabs/window_finder_mus.cc",
           "views/tabs/window_finder_mus.h",
         ]