Fix sensors layout tests flakiness

third_party/WebKit/LayoutTests/sensor/resources/generic-sensor-tests.js

Index: third_party/WebKit/LayoutTests/sensor/resources/generic-sensor-tests.js
diff --git a/third_party/WebKit/LayoutTests/sensor/resources/generic-sensor-tests.js b/third_party/WebKit/LayoutTests/sensor/resources/generic-sensor-tests.js
index fc1fc8ed316a9d98204c4853717e2f68f9ba8f2a..82c6ce6c818b49f739b0fa272867462b75fabad5 100644
--- a/third_party/WebKit/LayoutTests/sensor/resources/generic-sensor-tests.js
+++ b/third_party/WebKit/LayoutTests/sensor/resources/generic-sensor-tests.js
@@ -310,7 +310,7 @@ function runGenericSensorTests(sensorType, updateReading, verifyReading) {
                 // (not to a timer) so fluctuations are possible, so we
                 // reference to the actual elapsed updates count.
                 let elapsedUpdates = mockSensor.reading_updates_count() - readingUpdatesCounter;
-                assert_equals(fastSensorNotifiedCounter, elapsedUpdates);
+                assert_approx_equals(fastSensorNotifiedCounter, elapsedUpdates, 1);
                 fastSensor.stop();
                 slowSensor.stop();
                 resolve(mockSensor);