service worker: Add instrumentation for crash on bad timing.

The crash is a renderer kill when the browser receives timing data
that goes back in time. TimeTicks is supposed to be monotonically
increasing.

Bug: 881100
Change-Id: I3337b3e4102dfebfb3d2eeeb28cef85ecaf5e4ea
Reviewed-on: https://chromium-review.googlesource.com/c/1322251Reviewed-by: Makoto Shimazu <shimazu@chromium.org>
Commit-Queue: Matt Falkenhagen <falken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605989}

content/renderer/service_worker/service_worker_context_client.cc

@@ -737,6 +737,17 @@ void ServiceWorkerContextClient::WorkerContextStarted(
 void ServiceWorkerContextClient::WillEvaluateScript() {
   DCHECK(worker_task_runner_->RunsTasksInCurrentSequence());
   start_timing_->script_evaluation_start_time = base::TimeTicks::Now();
+
+  // Temporary CHECK for https://crbug.com/881100
+  int64_t t0 =
+      start_timing_->start_worker_received_time.since_origin().InMicroseconds();
+  int64_t t1 = start_timing_->script_evaluation_start_time.since_origin()
+                   .InMicroseconds();
+  base::debug::Alias(&t0);
+  base::debug::Alias(&t1);
+  CHECK_LE(start_timing_->start_worker_received_time,
+           start_timing_->script_evaluation_start_time);
+
   (*instance_host_)->OnScriptEvaluationStart();
 }
 
@@ -744,6 +755,16 @@ void ServiceWorkerContextClient::DidEvaluateScript(bool success) {
   DCHECK(worker_task_runner_->RunsTasksInCurrentSequence());
   start_timing_->script_evaluation_end_time = base::TimeTicks::Now();
 
+  // Temporary CHECK for https://crbug.com/881100
+  int64_t t0 = start_timing_->script_evaluation_start_time.since_origin()
+                   .InMicroseconds();
+  int64_t t1 =
+      start_timing_->script_evaluation_end_time.since_origin().InMicroseconds();
+  base::debug::Alias(&t0);
+  base::debug::Alias(&t1);
+  CHECK_LE(start_timing_->script_evaluation_start_time,
+           start_timing_->script_evaluation_end_time);
+
   blink::mojom::ServiceWorkerStartStatus status =
       success ? blink::mojom::ServiceWorkerStartStatus::kNormalCompletion
               : blink::mojom::ServiceWorkerStartStatus::kAbruptCompletion;
@@ -1368,6 +1389,21 @@ void ServiceWorkerContextClient::SendWorkerStarted(
         service_worker_version_id_, service_worker_scope_, script_url_);
   }
 
+  // Temporary CHECK for https://crbug.com/881100
+  int64_t t0 =
+      start_timing_->start_worker_received_time.since_origin().InMicroseconds();
+  int64_t t1 = start_timing_->script_evaluation_start_time.since_origin()
+                   .InMicroseconds();
+  int64_t t2 =
+      start_timing_->script_evaluation_end_time.since_origin().InMicroseconds();
+  base::debug::Alias(&t0);
+  base::debug::Alias(&t1);
+  base::debug::Alias(&t2);
+  CHECK_LE(start_timing_->start_worker_received_time,
+           start_timing_->script_evaluation_start_time);
+  CHECK_LE(start_timing_->script_evaluation_start_time,
+           start_timing_->script_evaluation_end_time);
+
   (*instance_host_)
       ->OnStarted(status, WorkerThread::GetCurrentId(),
                   std::move(start_timing_));