Move web modal dialog manager files into the constrained_window component.

components/web_modal/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.
 
 assert(!is_android && !is_ios)
 
 static_library("web_modal") {
   sources = [
     "modal_dialog_host.cc",
     "modal_dialog_host.h",
@@ skipping 16 matching lines @@
   ]
 }
 
 static_library("test_support") {
   testonly = true
   sources = [
     "test_web_contents_modal_dialog_host.cc",
     "test_web_contents_modal_dialog_host.h",
     "test_web_contents_modal_dialog_manager_delegate.cc",
     "test_web_contents_modal_dialog_manager_delegate.h",
+    "test_web_contents_modal_dialog_manager_views.cc",
   ]
 
   public_deps = [
     ":web_modal",
   ]
   deps = [
     "//base",
     "//ui/gfx",
     "//ui/gfx/geometry",
   ]
 }
 
 source_set("unit_tests") {
   testonly = true
 
   sources = [
     "web_contents_modal_dialog_manager_unittest.cc",
   ]
 
   deps = [
     ":test_support",
     ":web_modal",
     "//base",
     "//content/test:test_support",
     "//testing/gtest",
   ]
 }