scheduler: Avoid false alerts about expensive task blocking

components/scheduler/renderer/renderer_scheduler_impl.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/scheduler/renderer/renderer_scheduler_impl.h"
 
 #include "base/bind.h"
 #include "base/debug/stack_trace.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
@@ skipping 1276 matching lines @@
     const std::string& message) {
   helper_.CheckOnValidThread();
   for (auto& web_view_scheduler : MainThreadOnly().web_view_schedulers_)
     web_view_scheduler->AddConsoleWarning(message);
 }
 
 void RendererSchedulerImpl::OnTriedToExecuteBlockedTask(
     const TaskQueue& queue,
     const base::PendingTask& task) {
   if (!MainThreadOnly().expensive_task_blocking_allowed ||
+      MainThreadOnly().current_use_case == UseCase::TOUCHSTART ||
+      MainThreadOnly().longest_jank_free_task_duration <
+          base::TimeDelta::FromMilliseconds(kRailsResponseTimeMillis) ||
       MainThreadOnly().timer_queue_suspend_count ||
       MainThreadOnly().timer_queue_suspended_when_backgrounded) {
     return;
   }
+  if (!MainThreadOnly().timer_tasks_seem_expensive &&
+      !MainThreadOnly().loading_tasks_seem_expensive) {
+    return;
+  }
   if (!MainThreadOnly().have_reported_blocking_intervention_in_current_policy) {
     MainThreadOnly().have_reported_blocking_intervention_in_current_policy =
         true;
     TRACE_EVENT_INSTANT0("renderer.scheduler",
                          "RendererSchedulerImpl::TaskBlocked",
                          TRACE_EVENT_SCOPE_THREAD);
   }
 
   if (!MainThreadOnly().have_reported_blocking_intervention_since_navigation) {
     {
       base::AutoLock lock(any_thread_lock_);
       if (!AnyThread().have_seen_touchstart)
         return;
     }
     MainThreadOnly().have_reported_blocking_intervention_since_navigation =
         true;
     BroadcastConsoleWarning(
         "Blink deferred a task in order to make scrolling smoother. "
-        "Your timer tasks should take less than 50ms to run to avoid this. "
-        "Please see "
+        "Your timer and network tasks should take less than 50ms to run "
+        "to avoid this. Please see "
         "https://developers.google.com/web/tools/chrome-devtools/profile/evaluate-performance/rail"
         " and https://crbug.com/574343#c40 for more information.");
   }
 }
 
 }  // namespace scheduler