Bug 1585682 [wpt PR 19467] - [sensors] Round off Ambient Light Sensor…

… readouts to the nearest 50 Lux., a=testonly

Automatic update from web-platform-tests
[sensors] Round off Ambient Light Sensor readouts to the nearest 50 Lux.

There have been some concerns regarding the precision of readouts from the
Ambient Light Sensor. To decrease the entropy, we are rounding off the
illuminance value to the nearest 50 Lux to mitigate the known attack
vectors as summarized in [1].

[1] w3c/ambient-light#13 (comment)

This CL is based on
https://chromium-review.googlesource.com/c/chromium/src/+/1695412 by
Rijubrata Bhaumik and myself.

Bug: 642731, 606766
Change-Id: I85449bdb835e8486b080fc269938b6c96f000c2a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1834346
Reviewed-by: Reilly Grant <reillygchromium.org>
Reviewed-by: Kentaro Hara <harakenchromium.org>
Commit-Queue: Raphael Kubo da Costa <raphael.kubo.da.costaintel.com>
Cr-Commit-Position: refs/heads/master{#705486}

--

wpt-commits: b5c2b81b664dbf9fccf7316017ada0878fc10fa1
wpt-pr: 19467

UltraBlame original commit: 36a1b8d7d73706d8223e20f47649db4e8741d20f

testing/web-platform/tests/generic-sensor/generic-sensor-tests.js

@@ -2061,7 +2061,10 @@ correct
 sensor_test
 (
 async
+(
 t
+sensorProvider
+)
 =
 >
 {
@@ -2104,6 +2107,25 @@ start
 (
 )
 ;
+const
+mockSensor
+=
+await
+sensorProvider
+.
+getCreatedSensor
+(
+sensorName
+)
+;
+await
+mockSensor
+.
+setSensorReading
+(
+readings
+)
+;
 await
 sensorWatcher
 .
@@ -3217,6 +3239,14 @@ getCreatedSensor
 sensorName
 )
 ;
+await
+mockSensor
+.
+setSensorReading
+(
+readings
+)
+;
 const
 fastCounter
 =

testing/web-platform/tests/resources/chromium/generic_sensor_mocks.js

@@ -1409,6 +1409,144 @@ maxFrequency_
 )
 ;
 }
+/
+/
+Chromium
+applies
+some
+rounding
+and
+other
+privacy
+-
+related
+measures
+that
+/
+/
+can
+cause
+ALS
+not
+to
+report
+a
+reading
+when
+it
+has
+not
+changed
+beyond
+a
+/
+/
+certain
+threshold
+compared
+to
+the
+previous
+illuminance
+value
+.
+Make
+/
+/
+each
+reading
+return
+a
+different
+value
+that
+is
+significantly
+different
+/
+/
+from
+the
+previous
+one
+when
+setSensorReading
+(
+)
+is
+not
+called
+by
+client
+/
+/
+code
+(
+e
+.
+g
+.
+run_generic_sensor_iframe_tests
+(
+)
+)
+.
+if
+(
+type
+=
+=
+device
+.
+mojom
+.
+SensorType
+.
+AMBIENT_LIGHT
+)
+{
+this
+.
+activeSensors_
+.
+get
+(
+type
+)
+.
+setSensorReading
+(
+[
+[
+window
+.
+performance
+.
+now
+(
+)
+*
+100
+]
+[
+(
+window
+.
+performance
+.
+now
+(
+)
++
+50
+)
+*
+100
+]
+]
+)
+;
+}
 const
 initParams
 =