[base] Reduce TaskEnvironment default Run() timeout.

Reduce the default Run() timeout set by TaskEnvironment from
TestTimeouts::action_max_timeout() to action_timeout(). This typically
reduces the timeout from 30s (45s in Debug) down to 10s.

Sheriffs! This may result in:
- Failures on slow builds, which are not on CQ. Please consider adding
  an #ifdef to restore those builds to action_max_timeout(), rather
  than simply reverting.
- Flakiness in tests which are too close to the new timeout. Please
  consider whether such tests should really be taking so long, and
  whether they can be fixed-forward with a ScopedRunTimeoutForTest
  rather than reverting (see ThroughputAnalyzerTest in this CL).

Bug: 922098
Change-Id: Icd75af79f6d9d3555c91b33ea2566fe7c56cd2f7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1548382
Commit-Queue: Wez <wez@chromium.org>
Reviewed-by: Gabriel Charette <gab@chromium.org>
Reviewed-by: Maks Orlovich <morlovich@chromium.org>
Auto-Submit: Wez <wez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#695252}

base/test/task_environment.cc

@@ -363,14 +363,13 @@ TaskEnvironment::TaskEnvironment(
                                     : nullptr),
       scoped_lazy_task_runner_list_for_testing_(
           std::make_unique<internal::ScopedLazyTaskRunnerListForTesting>()),
-      // TODO(https://crbug.com/918724): Enable Run() timeouts even for
-      // instances created with *MOCK_TIME, and determine whether the timeout
-      // can be reduced from action_max_timeout() to action_timeout().
+      // TODO(https://crbug.com/922098): Enable Run() timeouts even for
+      // instances created with *MOCK_TIME.
       run_loop_timeout_(
           mock_time_domain_
               ? nullptr
               : std::make_unique<RunLoop::ScopedRunTimeoutForTest>(
-                    TestTimeouts::action_max_timeout(),
+                    TestTimeouts::action_timeout(),
                     MakeExpectedNotRunClosure(FROM_HERE,
                                               "RunLoop::Run() timed out."))) {
   CHECK(!base::ThreadTaskRunnerHandle::IsSet());

net/nqe/throughput_analyzer_unittest.cc

@@ -20,8 +20,10 @@
 #include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/test/bind_test_util.h"
 #include "base/test/metrics/histogram_tester.h"
 #include "base/test/simple_test_tick_clock.h"
+#include "base/test/test_timeouts.h"
 #include "base/threading/platform_thread.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/default_tick_clock.h"
@@ -704,6 +706,10 @@ TEST_F(ThroughputAnalyzerTest, TestThroughputWithNetworkRequestsOverlap) {
 // of network requests overlap, and the minimum number of in flight requests
 // when taking an observation is more than 1.
 TEST_F(ThroughputAnalyzerTest, TestThroughputWithMultipleNetworkRequests) {
+  const base::RunLoop::ScopedRunTimeoutForTest increased_run_timeout(
+      TestTimeouts::action_max_timeout(),
+      base::MakeExpectedNotRunClosure(FROM_HERE, "RunLoop::Run() timed out."));
+
   const base::TickClock* tick_clock = base::DefaultTickClock::GetInstance();
   TestNetworkQualityEstimator network_quality_estimator;
   std::map<std::string, std::string> variation_params;