Use CONTINUE_ON_SHUTDOWN for IncidentReportingService tasks.

chrome/browser/safe_browsing/incident_reporting/incident_reporting_service.cc

Index: chrome/browser/safe_browsing/incident_reporting/incident_reporting_service.cc
diff --git a/chrome/browser/safe_browsing/incident_reporting/incident_reporting_service.cc b/chrome/browser/safe_browsing/incident_reporting/incident_reporting_service.cc
index ecd5aea00c37a709850e1d041e917bebcd7026b6..a8df1e34edbd1bf4be2637dbf40439f7cc6de0f6 100644
--- a/chrome/browser/safe_browsing/incident_reporting/incident_reporting_service.cc
+++ b/chrome/browser/safe_browsing/incident_reporting/incident_reporting_service.cc
@@ -22,6 +22,7 @@
 #include "base/thread_task_runner_handle.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "build/build_config.h"
+#include "chrome/browser/browser_hangs_experiment.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/metrics/chrome_metrics_service_accessor.h"
 #include "chrome/browser/profiles/profile.h"
@@ -146,6 +147,15 @@ bool ProfileCanAcceptIncident(Profile* profile, const Incident& incident) {
   return false;
 }
 
+// Returns the shutdown behavior for the task runners of the incident reporting
+// service. Current metrics suggest that CONTINUE_ON_SHUTDOWN will reduce the
+// number of browser hangs on shutdown.
+base::SequencedWorkerPool::WorkerShutdown GetShutdownBehavior() {
+  return IsBrowserHangsExperimentEnabled()
+             ? base::SequencedWorkerPool::CONTINUE_ON_SHUTDOWN
+             : base::SequencedWorkerPool::SKIP_ON_SHUTDOWN;
+}
+
 }  // namespace
 
 struct IncidentReportingService::ProfileContext {
@@ -338,8 +348,7 @@ IncidentReportingService::IncidentReportingService(
       collect_environment_data_fn_(&CollectEnvironmentData),
       environment_collection_task_runner_(
           content::BrowserThread::GetBlockingPool()
-              ->GetTaskRunnerWithShutdownBehavior(
-                  base::SequencedWorkerPool::SKIP_ON_SHUTDOWN)),
+              ->GetTaskRunnerWithShutdownBehavior(GetShutdownBehavior())),
       environment_collection_pending_(),
       collation_timeout_pending_(),
       collation_timer_(FROM_HERE,
@@ -349,13 +358,11 @@ IncidentReportingService::IncidentReportingService(
       delayed_analysis_callbacks_(
           base::TimeDelta::FromMilliseconds(kDefaultCallbackIntervalMs),
           content::BrowserThread::GetBlockingPool()
-              ->GetTaskRunnerWithShutdownBehavior(
-                  base::SequencedWorkerPool::SKIP_ON_SHUTDOWN)),
+              ->GetTaskRunnerWithShutdownBehavior(GetShutdownBehavior())),
       extended_reporting_only_delayed_analysis_callbacks_(
           base::TimeDelta::FromMilliseconds(kDefaultCallbackIntervalMs),
           content::BrowserThread::GetBlockingPool()
-              ->GetTaskRunnerWithShutdownBehavior(
-                  base::SequencedWorkerPool::SKIP_ON_SHUTDOWN)),
+              ->GetTaskRunnerWithShutdownBehavior(GetShutdownBehavior())),
       download_metadata_manager_(content::BrowserThread::GetBlockingPool()),
       receiver_weak_ptr_factory_(this),
       weak_ptr_factory_(this) {
@@ -463,8 +470,7 @@ IncidentReportingService::IncidentReportingService(
       collect_environment_data_fn_(&CollectEnvironmentData),
       environment_collection_task_runner_(
           content::BrowserThread::GetBlockingPool()
-              ->GetTaskRunnerWithShutdownBehavior(
-                  base::SequencedWorkerPool::SKIP_ON_SHUTDOWN)),
+              ->GetTaskRunnerWithShutdownBehavior(GetShutdownBehavior())),
       environment_collection_pending_(),
       collation_timeout_pending_(),
       collation_timer_(FROM_HERE,
@@ -497,8 +503,7 @@ void IncidentReportingService::SetCollectEnvironmentHook(
     collect_environment_data_fn_ = &CollectEnvironmentData;
     environment_collection_task_runner_ =
         content::BrowserThread::GetBlockingPool()
-            ->GetTaskRunnerWithShutdownBehavior(
-                base::SequencedWorkerPool::SKIP_ON_SHUTDOWN);
+            ->GetTaskRunnerWithShutdownBehavior(GetShutdownBehavior());
   }
 }