Move web modal dialog manager files into the constrained_window component.

components/constrained_window/test_create_native_web_modal_manager_cocoa.cc

Index: components/constrained_window/test_create_native_web_modal_manager_cocoa.cc
diff --git a/extensions/shell/browser/shell_web_contents_modal_dialog_manager.cc b/components/constrained_window/test_create_native_web_modal_manager_cocoa.cc
similarity index 61%
rename from extensions/shell/browser/shell_web_contents_modal_dialog_manager.cc
rename to components/constrained_window/test_create_native_web_modal_manager_cocoa.cc
index 266f37960dfc8ffa4f482861fd42b3cb24f21708..931dfe45c39b554c32f342506cedd8e4681a5c59 100644
--- a/extensions/shell/browser/shell_web_contents_modal_dialog_manager.cc
+++ b/components/constrained_window/test_create_native_web_modal_manager_cocoa.cc
@@ -1,4 +1,4 @@
-// Copyright 2014 The Chromium Authors. All rights reserved.
+// Copyright 2016 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.
 
@@ -9,10 +9,8 @@ namespace web_modal {
 SingleWebContentsDialogManager*
 WebContentsModalDialogManager::CreateNativeWebModalManager(
     gfx::NativeWindow dialog,
-    SingleWebContentsDialogManagerDelegate* native_delegate) {
-  // TODO(oshima): Investigate if we need to implement this.
-  NOTREACHED();
-  return NULL;
+    web_modal::SingleWebContentsDialogManagerDelegate* delegate) {
+  return nullptr;
 }
 
 }  // namespace web_modal