Revert "Migrate consumers of SigninManager::IsAllowedUsername()"

This reverts commit 198eca95.

Reason for revert: breaking GPU Linux Builder

Original change's description:
> Migrate consumers of SigninManager::IsAllowedUsername()
> 
> Use identity::IsUsernameAllowedByPattern() instead so that we can migrate
> those consumers entirely to the IdentityManager in follow-up patches.
> 
> Also, in order to make it explicit that this API should not be used any
> more, make SigninManager::IsAllowedUsername() a private method and friend
> it with the relevant test cases from SigninManagerTest, so that it can
> only be used from there. And while at it, also remove some stale lines
> "friending" SigninManager with test cases that no longer exist.
> 
> Bug: 890794, 890815, 906085
> Change-Id: Id8a72b0efd89818e02c6d1e73aac1451207b9625
> Reviewed-on: https://chromium-review.googlesource.com/c/1346409
> Reviewed-by: Mihai Sardarescu <msarda@chromium.org>
> Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
> Commit-Queue: Mario Sanchez Prada <mario@igalia.com>
> Cr-Commit-Position: refs/heads/master@{#611704}

TBR=blundell@chromium.org,msarda@chromium.org,sdefresne@chromium.org,mario@igalia.com

Change-Id: I8172674e32d7671868fa5374a9457abd6413321e
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 890794, 890815, 906085
Reviewed-on: https://chromium-review.googlesource.com/c/1354121Reviewed-by: Ned Nguyen <nednguyen@google.com>
Commit-Queue: Ned Nguyen <nednguyen@google.com>
Cr-Commit-Position: refs/heads/master@{#611710}

chrome/browser/signin/signin_ui_util.cc

@@ -11,7 +11,6 @@
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "build/build_config.h"
-#include "chrome/browser/browser_process.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/signin/account_tracker_service_factory.h"
 #include "chrome/browser/signin/gaia_cookie_manager_service_factory.h"
@@ -32,9 +31,7 @@
 #include "components/signin/core/browser/account_info.h"
 #include "components/signin/core/browser/account_tracker_service.h"
 #include "components/signin/core/browser/gaia_cookie_manager_service.h"
-#include "components/signin/core/browser/identity_utils.h"
 #include "components/signin/core/browser/signin_manager.h"
-#include "components/signin/core/browser/signin_pref_names.h"
 #include "components/user_manager/user_manager.h"
 #include "services/identity/public/cpp/identity_manager.h"
 #include "third_party/re2/src/re2/re2.h"
@@ -243,9 +240,7 @@ std::vector<AccountInfo> GetAccountsForDicePromos(Profile* profile) {
   std::vector<AccountInfo> accounts;
   for (auto account_info : accounts_with_tokens) {
     DCHECK(!account_info.IsEmpty());
-    if (!identity::LegacyIsUsernameAllowedByPatternFromPrefs(
-            g_browser_process->local_state(), account_info.email,
-            prefs::kGoogleServicesUsernamePattern)) {
+    if (!signin_manager->IsAllowedUsername(account_info.email)) {
       continue;
     }
     if (account_info.account_id == default_account_id)

chrome/browser/ui/webui/signin/signin_utils_desktop.cc

@@ -18,7 +18,6 @@
 #include "chrome/grit/chromium_strings.h"
 #include "chrome/grit/generated_resources.h"
 #include "components/guest_view/browser/guest_view_manager.h"
-#include "components/signin/core/browser/identity_utils.h"
 #include "components/signin/core/browser/signin_manager.h"
 #include "components/signin/core/browser/signin_pref_names.h"
 #include "ui/base/l10n/l10n_util.h"
@@ -46,9 +45,7 @@ bool CanOfferSignin(Profile* profile,
       return false;
 
     // Make sure this username is not prohibited by policy.
-    if (!identity::LegacyIsUsernameAllowedByPatternFromPrefs(
-            g_browser_process->local_state(), email,
-            prefs::kGoogleServicesUsernamePattern)) {
+    if (!manager->IsAllowedUsername(email)) {
       if (error_message) {
         error_message->assign(
             l10n_util::GetStringUTF8(IDS_SYNC_LOGIN_NAME_PROHIBITED));

components/signin/core/browser/signin_manager.h

@@ -168,6 +168,10 @@ class SigninManager : public SigninManagerBase,
   // Sets whether sign-in is allowed or not.
   void SetSigninAllowed(bool allowed);
 
+  // Returns true if the passed username is allowed by policy. Virtual for
+  // mocking in tests.
+  virtual bool IsAllowedUsername(const std::string& username) const;
+
   // If an authentication is in progress, return the account id being
   // authenticated. Returns an empty string if no auth is in progress.
   const std::string& GetAccountIdForAuthInProgress() const;
@@ -198,8 +202,9 @@ class SigninManager : public SigninManagerBase,
   std::string SigninTypeToString(SigninType type);
   friend class FakeSigninManager;
   friend class identity::IdentityManager;
-  FRIEND_TEST_ALL_PREFIXES(SigninManagerTest, Prohibited);
-  FRIEND_TEST_ALL_PREFIXES(SigninManagerTest, TestAlternateWildcard);
+  FRIEND_TEST_ALL_PREFIXES(SigninManagerTest, ClearTransientSigninData);
+  FRIEND_TEST_ALL_PREFIXES(SigninManagerTest, ProvideSecondFactorSuccess);
+  FRIEND_TEST_ALL_PREFIXES(SigninManagerTest, ProvideSecondFactorFailure);
 
   // Called to setup the transient signin data during one of the
   // StartSigninXXX methods.  |type| indicates which of the methods is being
@@ -251,9 +256,6 @@ class SigninManager : public SigninManagerBase,
   void OnSigninAllowedPrefChanged();
   void OnGoogleServicesUsernamePatternChanged();
 
-  // Returns true if the passed username is allowed by policy.
-  bool IsAllowedUsername(const std::string& username) const;
-
   std::string possibly_invalid_account_id_;
   std::string possibly_invalid_gaia_id_;
   std::string possibly_invalid_email_;