[sensors] Fix flakiness in generic sensors tests

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

 'use strict';
 
 // Run a set of tests for a given |sensorType|. |updateReading| is
 // a called by the test to provide the mock values for sensor. |verifyReading|
 // is called so that the value read in JavaScript are the values expected (the ones
 // sent by |updateReading|).
 function runGenericSensorTests(sensorType, updateReading, verifyReading) {
   test(() => assert_throws(
     new RangeError(),
     () => new sensorType({frequency: -60})),
     'Test that negative frequency causes exception from constructor.');
 
   sensor_test(sensor => {
     sensor.mockSensorProvider.setGetSensorShouldFail(true);
     let sensorObject = new sensorType;
     sensorObject.start();
     return new Promise((resolve, reject) => {
       let wrapper = new CallbackWrapper(event => {
         assert_equals(sensorObject.state, 'errored');
-        console.log(event.error.message);
         assert_equals(event.error.name, 'NotFoundError');
         sensorObject.onerror = null;
         resolve();
       }, reject);
 
       sensorObject.onerror = wrapper.callback;
     });
   }, 'Test that "onerror" is send when sensor is not supported.');
 
   sensor_test(sensor => {
@@ skipping 157 matching lines @@
 
   sensor_test(sensor => {
     let sensorObject = new sensorType;
     sensorObject.start();
     let testPromise = sensor.mockSensorProvider.getCreatedSensor()
         .then(mockSensor => {
           return mockSensor.setUpdateSensorReadingFunction(updateReading);
         })
         .then(mockSensor => {
           return new Promise((resolve, reject) => {
-            sensorObject.onchange = () => {
-              if (verifyReading(sensorObject.reading)) {
-                resolve(mockSensor);
-              }
-            }
-          sensorObject.onerror = reject;
+            let wrapper = new CallbackWrapper(() => {
+              assert_true(verifyReading(sensorObject.reading));
+              resolve(mockSensor);
+            }, reject);
+
+            sensorObject.onchange = wrapper.callback;
+            sensorObject.onerror = reject;
           });
         })
         .then(mockSensor => {
           testRunner.setPageVisibility('hidden');
           return mockSensor.suspendCalled();
         })
         .then(mockSensor => {
           testRunner.setPageVisibility('visible');
           return mockSensor.resumeCalled();
         })
@@ skipping 47 matching lines @@
           sensor1.onchange = wrapper.callback;
           sensor1.onerror = reject;
           sensor2.onerror = reject;
         });
       })
       .then(mockSensor => { return mockSensor.removeConfigurationCalled(); });
 
   return testPromise;
 }, 'Test that sensor reading is correct.');
 }