Fix DCHECK when upgrading from an old profile.

components/signin/core/browser/account_tracker_service.cc

 // 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.
 
 #include "components/signin/core/browser/account_tracker_service.h"
 
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/metrics/field_trial.h"
@@ skipping 237 matching lines @@
     const std::string& account_id) {
   if (ContainsKey(accounts_, account_id))
     return accounts_[account_id].info;
 
   return AccountInfo();
 }
 
 AccountTrackerService::AccountInfo
 AccountTrackerService::FindAccountInfoByGaiaId(
     const std::string& gaia_id) {
-  for (std::map<std::string, AccountState>::const_iterator it =
-           accounts_.begin();
-       it != accounts_.end();
-       ++it) {
-    const AccountState& state = it->second;
-    if (state.info.gaia == gaia_id)
-      return state.info;
+  if (!gaia_id.empty()) {

[Mike Lerman, 2015/04/24 12:43:09]

nit: informal style seems to be that, rather than doing if (!condition) { <some
long block> } return, you instead do: if (condition) return; <some long block>

This (and FindAccountInfoByEmail) would turn into: if (gaia_id.empty()) return
AccountInfo(); for (...)

I don't feel at all strongly about this and you can leave this as is if you
prefer.

[Roger Tawa OOO till Jul 10th, 2015/04/24 13:00:33]

I think I'll leave.it as is.

+    for (std::map<std::string, AccountState>::const_iterator it =
+             accounts_.begin();
+         it != accounts_.end();
+         ++it) {
+      const AccountState& state = it->second;
+      if (state.info.gaia == gaia_id)
+        return state.info;
+    }
   }
 
   return AccountInfo();
 }
 
 AccountTrackerService::AccountInfo
 AccountTrackerService::FindAccountInfoByEmail(
     const std::string& email) {
-  for (std::map<std::string, AccountState>::const_iterator it =
-           accounts_.begin();
-       it != accounts_.end();
-       ++it) {
-    const AccountState& state = it->second;
-    if (gaia::AreEmailsSame(state.info.email, email))
-      return state.info;
+  if (!email.empty()) {
+    for (std::map<std::string, AccountState>::const_iterator it =
+             accounts_.begin();
+         it != accounts_.end();
+         ++it) {
+      const AccountState& state = it->second;
+      if (gaia::AreEmailsSame(state.info.email, email))
+        return state.info;
+    }
   }
 
   return AccountInfo();
 }
 
 AccountTrackerService::AccountIdMigrationState
 AccountTrackerService::GetMigrationState() {
   return GetMigrationState(signin_client_->GetPrefs());
 }
 
@@ skipping 287 matching lines @@
     const std::string& gaia,
     const std::string& email) {
   return PickAccountIdForAccount(signin_client_->GetPrefs(), gaia, email);
 }
 
 // static
 std::string AccountTrackerService::PickAccountIdForAccount(
     PrefService* pref_service,
     const std::string& gaia,
     const std::string& email) {
-  DCHECK(!gaia.empty());
+  DCHECK(!gaia.empty() ||
+      GetMigrationState(pref_service) == MIGRATION_NOT_STARTED);
   DCHECK(!email.empty());
   switch(GetMigrationState(pref_service)) {
     case MIGRATION_NOT_STARTED:
     case MIGRATION_IN_PROGRESS:
       // Some tests don't use a real email address.  To support these cases,
       // don't try to canonicalize these strings.
       return (email.find('@') == std::string::npos) ? email :
           gaia::CanonicalizeEmail(email);
     case MIGRATION_DONE:
       return gaia;
     default:
       NOTREACHED();
       return email;
   }
 }
 
 std::string AccountTrackerService::SeedAccountInfo(const std::string& gaia,
                                                    const std::string& email) {
-  DCHECK(!gaia.empty());
-  DCHECK(!email.empty());
   const std::string account_id = PickAccountIdForAccount(gaia, email);
   const bool already_exists = ContainsKey(accounts_, account_id);
   StartTrackingAccount(account_id);
   AccountState& state = accounts_[account_id];
-  DCHECK(!already_exists || state.info.gaia == gaia);
+  DCHECK(!already_exists || state.info.gaia.empty() || state.info.gaia == gaia);
   state.info.gaia = gaia;
   state.info.email = email;
   SaveToPrefs(state);
 
   DVLOG(1) << "AccountTrackerService::SeedAccountInfo"
            << " account_id=" << account_id
            << " gaia_id=" << gaia
            << " email=" << email;
 
   return account_id;
 }