[signin] Dont delete DiceTurnSyncOnHelper from its constructor

This seems to be undefined behavior and is caught by the ASAN bot.

Bug: 816372
Change-Id: I16435111c860115bf288798b0c88ea9e37daf147
Reviewed-on: https://chromium-review.googlesource.com/948843Reviewed-by: Mihai Sardarescu <msarda@chromium.org>
Commit-Queue: David Roger <droger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#541061}

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

@@ -5,11 +5,13 @@
 #include "chrome/browser/ui/webui/signin/dice_turn_sync_on_helper.h"
 
 #include "base/bind.h"
+#include "base/location.h"
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/user_metrics.h"
 #include "base/metrics/user_metrics_action.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/threading/sequenced_task_runner_handle.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/policy/cloud/user_policy_signin_service.h"
 #include "chrome/browser/policy/cloud/user_policy_signin_service_factory.h"
@@ -71,7 +73,10 @@ DiceTurnSyncOnHelper::DiceTurnSyncOnHelper(
   DCHECK(!signin_util::IsForceSigninEnabled());
 
   if (HasCanOfferSigninError()) {
-    AbortAndDelete();
+    // Do not self-destruct synchronously in the constructor.
+    base::SequencedTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE, base::BindOnce(&DiceTurnSyncOnHelper::AbortAndDelete,
+                                  base::Unretained(this)));
     return;
   }
 

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

@@ -428,6 +428,7 @@ TEST_F(DiceTurnSyncOnHelperTest, CanOfferSigninErrorKeepAccount) {
   // Signin flow.
   CreateDiceTurnOnSyncHelper(
       DiceTurnSyncOnHelper::SigninAbortedMode::KEEP_ACCOUNT);
+  base::RunLoop().RunUntilIdle();
   // Check expectations.
   EXPECT_FALSE(signin_manager()->IsAuthenticated());
   EXPECT_TRUE(token_service()->RefreshTokenIsAvailable(account_id()));
@@ -443,6 +444,7 @@ TEST_F(DiceTurnSyncOnHelperTest, CanOfferSigninErrorRemoveAccount) {
   // Signin flow.
   CreateDiceTurnOnSyncHelper(
       DiceTurnSyncOnHelper::SigninAbortedMode::REMOVE_ACCOUNT);
+  base::RunLoop().RunUntilIdle();
   // Check expectations.
   EXPECT_FALSE(signin_manager()->IsAuthenticated());
   EXPECT_FALSE(token_service()->RefreshTokenIsAvailable(account_id()));