Prevent augmentRepeatInterval from computing a negative delay

third_party/WebKit/Source/platform/TimerTest.cpp

 // 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/Timer.h"
 
 #include "platform/testing/TestingPlatformSupport.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebScheduler.h"
 #include "public/platform/WebThread.h"
@@ skipping 681 matching lines @@
     advanceTimeBy(2.0);
     timer.augmentRepeatInterval(10);
 
     EXPECT_FLOAT_EQ(20.0, timer.repeatInterval());
     EXPECT_FLOAT_EQ(18.0, timer.nextFireInterval());
 
     runUntilIdleOrDeadlinePassed(m_startTime + 50.0);
     EXPECT_THAT(m_runTimes, ElementsAre(m_startTime + 20.0, m_startTime + 40.0));
 }
 
+TEST_F(TimerTest, AugmentRepeatInterval_TimerFireDelayed)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startRepeating(10, BLINK_FROM_HERE);
+    EXPECT_FLOAT_EQ(10.0, timer.repeatInterval());
+    EXPECT_FLOAT_EQ(10.0, timer.nextFireInterval());
+
+    advanceTimeBy(123.0); // Make the timer long overdue.
+    timer.augmentRepeatInterval(10);
+
+    EXPECT_FLOAT_EQ(20.0, timer.repeatInterval());
+    // The timer is overdue so it should be scheduled to fire immediatly.
+    EXPECT_FLOAT_EQ(0.0, timer.nextFireInterval());
+}
+
 TEST_F(TimerTest, RepeatingTimerDoesNotDrift)
 {
     Timer<TimerTest> timer(this, &TimerTest::recordNextFireTimeTask);
     timer.startRepeating(2.0, BLINK_FROM_HERE);
 
     ASSERT(hasOneTimerTask());
     recordNextFireTimeTask(&timer); // Next scheduled task to run at m_startTime + 2.0
 
     // Simulate timer firing early. Next scheduled task to run at m_startTime + 4.0
     advanceTimeBy(1.9);
@@ skipping 49 matching lines @@
     TimerForTest<TimerTest> timer(this, &TimerTest::countingTask, &taskRunner);
     timer.startOneShot(0, BLINK_FROM_HERE);
 
     // Make sure the task was posted on taskRunner.
     EXPECT_FALSE(timerTasks.empty());
 }
 
 
 } // namespace
 } // namespace blink