Update avatar button to MD (part 1)

chrome/browser/ui/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/chromecast_build.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//build/split_static_library.gni")
 import("//chrome/common/features.gni")
@@ skipping 2018 matching lines @@
       "sync/one_click_signin_sync_observer.cc",
       "sync/one_click_signin_sync_observer.h",
       "sync/one_click_signin_sync_starter.cc",
       "sync/one_click_signin_sync_starter.h",
       "views/external_protocol_dialog.cc",
       "views/external_protocol_dialog.h",
       "views/frame/avatar_button_manager.cc",
       "views/frame/avatar_button_manager.h",
       "views/profiles/avatar_button.cc",
       "views/profiles/avatar_button.h",
-      "views/profiles/avatar_button_delegate.h",
       "views/profiles/avatar_button_style.h",
       "webui/app_launcher_page_ui.cc",
       "webui/app_launcher_page_ui.h",
       "webui/settings/settings_default_browser_handler.cc",
       "webui/settings/settings_default_browser_handler.h",
       "webui/settings/system_handler.cc",
       "webui/settings/system_handler.h",
       "webui/settings_utils_linux.cc",
       "webui/settings_utils_mac.mm",
       "webui/settings_utils_win.cc",
@@ skipping 1547 matching lines @@
       "test/test_confirm_bubble_model.cc",
       "test/test_confirm_bubble_model.h",
     ]
     deps += [ "//chrome/test:test_support_ui" ]
   }
 
   if (enable_extensions) {
     deps += [ "//extensions/browser" ]
   }
 }