[Sensors] Reland: Reland: Align sensor reading updates and 'onchange' notification with rAF.

third_party/WebKit/LayoutTests/sensor/ambient-light-sensor.html

Index: third_party/WebKit/LayoutTests/sensor/ambient-light-sensor.html
diff --git a/third_party/WebKit/LayoutTests/sensor/ambient-light-sensor.html b/third_party/WebKit/LayoutTests/sensor/ambient-light-sensor.html
index 282f6336ab5bf419537492d43f168d03bcb16ee3..63b18830dc6846af615f6496ad360296c9f4c47d 100644
--- a/third_party/WebKit/LayoutTests/sensor/ambient-light-sensor.html
+++ b/third_party/WebKit/LayoutTests/sensor/ambient-light-sensor.html
@@ -12,15 +12,12 @@ if (!window.testRunner)
     debug('This test cannot be run without the TestRunner');
 
 const kDefaultReadingValue = 3.1415;
-var readsCount = 0;
 
-function update_sensor_reading(buffer, expects_modified_reading) {
+function update_sensor_reading(buffer, expects_modified_reading, readsCount) {
   buffer[1] = window.performance.now();
   buffer[2] = kDefaultReadingValue;
   if (expects_modified_reading)
     buffer[2] += readsCount;
-
-  readsCount++;
 }
 
 function verify_sensor_reading(reading) {