Don't throttle web views until they've been in the background for 10s

third_party/WebKit/Source/platform/scheduler/renderer/web_view_scheduler_impl_unittest.cc

 // Copyright 2015 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 "platform/scheduler/renderer/web_view_scheduler_impl.h"
 
 #include <memory>
 
 #include "base/callback.h"
 #include "base/memory/ptr_util.h"
@@ skipping 92 matching lines @@
   int run_count = 0;
   web_frame_scheduler_->timerTaskRunner()->postDelayedTask(
       BLINK_FROM_HERE,
       makeRepeatingTask(web_frame_scheduler_->timerTaskRunner(), &run_count),
       1.0);
 
   mock_task_runner_->RunForPeriod(base::TimeDelta::FromSeconds(1));
   EXPECT_EQ(1000, run_count);
 }
 
-TEST_F(WebViewSchedulerImplTest, RepeatingTimer_PageInBackground) {
+TEST_F(WebViewSchedulerImplTest,
+       RepeatingTimer_PageInBackgroundThenForeground) {
   web_view_scheduler_->setPageVisible(false);
 
   int run_count = 0;
   web_frame_scheduler_->timerTaskRunner()->postDelayedTask(
       BLINK_FROM_HERE,
       makeRepeatingTask(web_frame_scheduler_->timerTaskRunner(), &run_count),
       1.0);
 
   mock_task_runner_->RunForPeriod(base::TimeDelta::FromSeconds(1));
+  EXPECT_EQ(1000, run_count);
+
+  // The task queue isn't throttled at all until it's been in the background for
+  // a 10 second grace period.
+  clock_->Advance(base::TimeDelta::FromSeconds(10));
+
+  run_count = 0;
+  mock_task_runner_->RunForPeriod(base::TimeDelta::FromSeconds(1));
   EXPECT_EQ(1, run_count);
+
+  // Make sure there's no delay in throttling being removed for pages that have
+  // become visible.
+  web_view_scheduler_->setPageVisible(true);
+
+  run_count = 0;
+  mock_task_runner_->RunForPeriod(base::TimeDelta::FromSeconds(1));
+  EXPECT_EQ(1001, run_count);  // Note we end up running 1001 here because the
+  // task was posted while throttled with a delay of 1ms so the first task was
+  // due to run before the 1s period started.
 }
 
 TEST_F(WebViewSchedulerImplTest, RepeatingLoadingTask_PageInBackground) {
   web_view_scheduler_->setPageVisible(false);
 
   int run_count = 0;
   web_frame_scheduler_->loadingTaskRunner()->postDelayedTask(
       BLINK_FROM_HERE,
       makeRepeatingTask(web_frame_scheduler_->loadingTaskRunner(), &run_count),
       1.0);
 
   mock_task_runner_->RunForPeriod(base::TimeDelta::FromSeconds(1));
   EXPECT_EQ(1000, run_count);  // Loading tasks should not be throttled
 }
 
 TEST_F(WebViewSchedulerImplTest, RepeatingTimers_OneBackgroundOneForeground) {
   std::unique_ptr<WebViewSchedulerImpl> web_view_scheduler2(
       new WebViewSchedulerImpl(nullptr, nullptr, scheduler_.get(), false));
   std::unique_ptr<WebFrameSchedulerImpl> web_frame_scheduler2 =
       web_view_scheduler2->createWebFrameSchedulerImpl(nullptr);
 
   web_view_scheduler_->setPageVisible(true);
   web_view_scheduler2->setPageVisible(false);
 
+  // Advance past the no-throttling grace period.
+  clock_->Advance(base::TimeDelta::FromSeconds(10));
+
   int run_count1 = 0;
   int run_count2 = 0;
   web_frame_scheduler_->timerTaskRunner()->postDelayedTask(
       BLINK_FROM_HERE,
       makeRepeatingTask(web_frame_scheduler_->timerTaskRunner(), &run_count1),
       1.0);
   web_frame_scheduler2->timerTaskRunner()->postDelayedTask(
       BLINK_FROM_HERE,
       makeRepeatingTask(web_frame_scheduler2->timerTaskRunner(), &run_count2),
       1.0);
@@ skipping 420 matching lines @@
       nullptr, &web_view_scheduler_settings, scheduler_.get(), false));
   web_frame_scheduler_ =
       web_view_scheduler_->createWebFrameSchedulerImpl(nullptr);
   web_view_scheduler_->setPageVisible(false);
 
   mock_task_runner_->RunUntilTime(base::TimeTicks() +
                                   base::TimeDelta::FromMilliseconds(2500));
 
   web_frame_scheduler_->timerTaskRunner()->postDelayedTask(
       BLINK_FROM_HERE, base::Bind(&ExpensiveTestTask, clock_.get(), &run_times),
-      0.1);
+      1);
   web_frame_scheduler_->timerTaskRunner()->postDelayedTask(
       BLINK_FROM_HERE, base::Bind(&ExpensiveTestTask, clock_.get(), &run_times),
-      0.1);
+      1);
 
   mock_task_runner_->RunUntilTime(base::TimeTicks() +
                                   base::TimeDelta::FromMilliseconds(3500));
 
-  // Check that these tasks are aligned, but are not subject to
-  // budget-based throttling.
+  // Check that these tasks are initially unthrottled.
   EXPECT_THAT(
       run_times,
-      ElementsAre(base::TimeTicks() + base::TimeDelta::FromMilliseconds(3000),
-                  base::TimeTicks() + base::TimeDelta::FromMilliseconds(3250)));
+      ElementsAre(base::TimeTicks() + base::TimeDelta::FromMilliseconds(2501),
+                  base::TimeTicks() + base::TimeDelta::FromMilliseconds(2751)));
   run_times.clear();
 
   mock_task_runner_->RunUntilTime(base::TimeTicks() +
                                   base::TimeDelta::FromMilliseconds(11500));
 
   web_frame_scheduler_->timerTaskRunner()->postDelayedTask(
       BLINK_FROM_HERE, base::Bind(&ExpensiveTestTask, clock_.get(), &run_times),
-      0.1);
+      1);
   web_frame_scheduler_->timerTaskRunner()->postDelayedTask(
       BLINK_FROM_HERE, base::Bind(&ExpensiveTestTask, clock_.get(), &run_times),
-      0.1);
+      1);
 
   mock_task_runner_->RunUntilIdle();
 
-  // Check that tasks are aligned and throttled.
+  // After the grace period has passed, tasks should be aligned and have budget
+  // based throttling.
   EXPECT_THAT(
       run_times,
       ElementsAre(base::TimeTicks() + base::TimeDelta::FromSeconds(12),
-                  base::TimeTicks() + base::TimeDelta::FromSeconds(29)));
+                  base::TimeTicks() + base::TimeDelta::FromSeconds(26)));
 }
 
 }  // namespace scheduler
 }  // namespace blink