Adding mediator for Sign-in promo

ios/chrome/browser/ui/authentication/BUILD.gn

 # 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.
 
 bundle_data("resources") {
   sources = [
     "resources/signin_confirmation_more.png",
     "resources/signin_confirmation_more@2x.png",
     "resources/signin_confirmation_more@3x.png",
   ]
@@ skipping 69 matching lines @@
   ]
 }
 
 source_set("authentication_arc") {
   configs += [ "//build/config/compiler:enable_arc" ]
   sources = [
     "account_control_item.h",
     "account_control_item.mm",
     "resized_avatar_cache.h",
     "resized_avatar_cache.mm",
+    "signin_promo_item.h",

[msarda, 2017/03/22 12:18:38]

Note that authentication_arc depends on the
//ios/public/provider/chrome/browser/signin which includes ChromeIdentity and
ChromeIdentityService etc. If the intent for this SigninPromoCell is never
depend on the model, then I suggest we move them to a new and different target -
maybe something like 'signin_promo_cell' that does not depend on
//ios/public/provider/chrome/browser/signin 

[lpromero, 2017/03/22 16:18:49]

Can you create a authentication_ui target in this file that will contain only
the UI layer (items, cells, views, view controllers)?
This is the target that Showcase should depend on for example.

[jlebel, 2017/03/24 20:59:08]

If I create authentication_ui target with all views and view controllers, I will
have to include //ios/public/provider/chrome/browser/signin since the rest do
mix UI and model API.
I need to put only my item, cell and view to be able to remove
//ios/public/provider/chrome/browser/signin

I don't use Showcase, I use "Cell Catalog".

[lpromero, 2017/03/27 13:14:46]

Right, I meant that the authentication_ui will ultimately contain these. In the
meantime, they contain as much UI as possible, which does not include VC yet, as
it has not been decoupled.

+    "signin_promo_item.mm",
+    "signin_promo_view.h",
+    "signin_promo_view.mm",
+    "signin_promo_view_mediator.h",
+    "signin_promo_view_mediator.mm",
   ]
   deps = [
+    "//base",
+    "//ios/chrome/app/strings",
     "//ios/chrome/browser/ui",
     "//ios/chrome/browser/ui/collection_view/cells",
     "//ios/chrome/browser/ui/colors",
     "//ios/public/provider/chrome/browser",
     "//ios/public/provider/chrome/browser/signin",
+    "//ui/base",
   ]
   libs = [
     "CoreGraphics.framework",
     "QuartzCore.framework",
     "UIKit.framework",
   ]
 }
 
 source_set("unit_tests") {
   configs += [ "//build/config/compiler:enable_arc" ]
   testonly = true
   sources = [
     "account_control_item_unittest.mm",
     "authentication_flow_unittest.mm",
     "re_signin_infobar_delegate_unittest.mm",
     "signed_in_accounts_view_controller_unittest.mm",
+    "signin_promo_item_unittest.mm",
+    "signin_promo_view_mediator_unittest.mm",
   ]
   deps = [
     ":authentication",
     ":authentication_arc",
     "//base",
     "//base/test:test_support",
     "//components/pref_registry",
     "//components/sync_preferences",
     "//components/sync_preferences:test_support",
     "//ios/chrome/browser/browser_state:test_support",
@@ skipping 32 matching lines @@
     "//ios/chrome/browser/ui/tools_menu",
     "//ios/chrome/test/app:test_support",
     "//ios/chrome/test/earl_grey:test_support",
     "//ios/public/provider/chrome/browser/signin:test_support",
     "//ios/testing:ios_test_support",
     "//ios/testing/earl_grey:earl_grey_support",
     "//ios/third_party/earl_grey",
   ]
   libs = [ "XCTest.framework" ]
 }