diff --git a/testing/web-platform/tests/clear-site-data/storage.https.html b/testing/web-platform/tests/clear-site-data/storage.https.html
index aee22dd079e2f..c4683385e5c63 100644
--- a/testing/web-platform/tests/clear-site-data/storage.https.html
+++ b/testing/web-platform/tests/clear-site-data/storage.https.html
@@ -48,6 +48,37 @@
 src
 =
 "
+.
+.
+/
+service
+-
+workers
+/
+service
+-
+worker
+/
+resources
+/
+test
+-
+helpers
+.
+sub
+.
+js
+"
+>
+<
+/
+script
+>
+<
+script
+src
+=
+"
 support
 /
 test_utils
@@ -114,6 +145,51 @@
 0
 ]
 ;
+var
+serviceWorkerTestPageIFrame
+;
+function
+fetchFromIFrame
+(
+)
+{
+return
+serviceWorkerTestPageIFrame
+.
+contentWindow
+.
+fetch
+(
+'
+support
+/
+controlled
+-
+endpoint
+.
+py
+'
+)
+.
+then
+(
+(
+result
+)
+=
+>
+{
+return
+result
+.
+text
+(
+)
+;
+}
+)
+;
+}
 /
 /
 The
@@ -190,10 +266,290 @@
 .
 then
 (
+(
+)
+=
+>
+{
+return
+new
+Promise
+(
+function
+(
+resolve
+reject
+)
+{
+promise_test
+(
+function
+(
+t
+)
+{
+return
+navigator
+.
+serviceWorker
+.
+getRegistration
+(
+"
+support
+/
+"
+)
+.
+then
+(
+function
+(
+reg
+)
+{
+return
+wait_for_state
+(
+t
+reg
+.
+installing
+|
+|
+reg
+.
+waiting
+|
+|
+reg
+.
+active
+'
+activated
+'
+)
+;
+}
+)
+.
+then
+(
+resolve
+reject
+)
+;
+}
+)
+;
+}
+)
+;
+}
+)
+.
+then
+(
+(
+)
+=
+>
+{
+return
+new
+Promise
+(
+function
+(
+resolve
+)
+{
+/
+/
+Create
+iFrame
+in
+the
+service
+worker
+'
+s
+scope
+.
+This
+page
+will
+make
+a
+request
+/
+/
+for
+another
+page
+that
+is
+only
+served
+by
+the
+service
+worker
+serviceWorkerTestPageIFrame
+=
+document
+.
+createElement
+(
+"
+iframe
+"
+)
+;
+serviceWorkerTestPageIFrame
+.
+src
+=
+"
+support
+/
+page_using_service_worker
+.
+html
+"
+;
+serviceWorkerTestPageIFrame
+.
+onload
+=
+function
+(
+)
+{
+resolve
+(
+)
+;
+}
+;
+document
+.
+body
+.
+appendChild
+(
+serviceWorkerTestPageIFrame
+)
+;
+}
+)
+;
+}
+)
+.
+then
+(
+(
+)
+=
+>
+{
+const
+serviceWorkerResponseBody
+=
+fetchFromIFrame
+(
+)
+;
+promise_test
+(
 function
 (
 )
 {
+return
+serviceWorkerResponseBody
+.
+then
+(
+function
+(
+body
+)
+{
+assert_equals
+(
+body
+"
+FROM_SERVICE_WORKER
+"
+"
+Response
+should
+be
+from
+service
+worker
+"
+)
+;
+}
+)
+;
+}
+"
+Baseline
+:
+Service
+worker
+responds
+to
+request
+"
+)
+;
+return
+serviceWorkerResponseBody
+;
+}
+)
+.
+then
+(
+function
+(
+)
+{
+const
+waitForControllerChange
+=
+new
+Promise
+(
+function
+(
+resolve
+)
+{
+serviceWorkerTestPageIFrame
+.
+contentWindow
+.
+navigator
+.
+serviceWorker
+.
+addEventListener
+(
+"
+controllerchange
+"
+resolve
+)
+;
+}
+)
+;
 /
 /
 Navigate
@@ -369,6 +725,115 @@
 }
 )
 ;
+promise_test
+(
+function
+(
+)
+{
+return
+fetchFromIFrame
+(
+)
+.
+then
+(
+function
+(
+body
+)
+{
+assert_equals
+(
+body
+"
+FROM_NETWORK
+"
+"
+Response
+should
+be
+from
+network
+and
+not
+from
+the
+service
+worker
+"
+)
+;
+}
+)
+;
+}
+"
+Service
+worker
+no
+longer
+responds
+to
+requests
+"
+)
+;
+promise_test
+(
+function
+(
+)
+{
+return
+waitForControllerChange
+.
+then
+(
+function
+(
+)
+{
+assert_false
+(
+!
+!
+serviceWorkerTestPageIFrame
+.
+contentWindow
+.
+navigator
+.
+serviceWorker
+.
+controller
+"
+Client
+should
+not
+have
+a
+controller
+"
+)
+;
+}
+)
+;
+}
+"
+controllerchange
+event
+fires
+and
+client
+no
+longer
+has
+controller
+"
+)
+;
 done
 (
 )
diff --git a/testing/web-platform/tests/clear-site-data/support/controlled-endpoint.py b/testing/web-platform/tests/clear-site-data/support/controlled-endpoint.py
new file mode 100644
index 0000000000000..1ac9535c0b868
--- /dev/null
+++ b/testing/web-platform/tests/clear-site-data/support/controlled-endpoint.py
@@ -0,0 +1,29 @@
+def
+main
+(
+request
+response
+)
+:
+    
+return
+(
+[
+(
+"
+Content
+-
+Type
+"
+"
+text
+/
+html
+"
+)
+]
+            
+"
+FROM_NETWORK
+"
+)
diff --git a/testing/web-platform/tests/clear-site-data/support/page_using_service_worker.html b/testing/web-platform/tests/clear-site-data/support/page_using_service_worker.html
new file mode 100644
index 0000000000000..70364402abec2
--- /dev/null
+++ b/testing/web-platform/tests/clear-site-data/support/page_using_service_worker.html
@@ -0,0 +1,36 @@
+<
+!
+DOCTYPE
+html
+>
+<
+html
+>
+<
+head
+>
+<
+title
+>
+Clear
+-
+Site
+-
+Data
++
+Service
+Workers
+Test
+Page
+<
+/
+title
+>
+<
+/
+head
+>
+<
+/
+html
+>
diff --git a/testing/web-platform/tests/clear-site-data/support/service_worker.js b/testing/web-platform/tests/clear-site-data/support/service_worker.js
index 4835dfee4b6d6..d0e8d6d5ad8b4 100644
--- a/testing/web-platform/tests/clear-site-data/support/service_worker.js
+++ b/testing/web-platform/tests/clear-site-data/support/service_worker.js
@@ -1,11 +1,61 @@
-/
-*
-This
-file
-is
-intentionally
-left
-blank
-.
-*
-/
+self
+.
+addEventListener
+(
+'
+fetch
+'
+(
+e
+)
+=
+>
+{
+const
+url
+=
+new
+URL
+(
+e
+.
+request
+.
+url
+)
+;
+if
+(
+url
+.
+pathname
+.
+match
+(
+'
+controlled
+-
+endpoint
+.
+py
+'
+)
+)
+{
+e
+.
+respondWith
+(
+new
+Response
+(
+'
+FROM_SERVICE_WORKER
+'
+)
+)
+;
+}
+}
+)
+;
diff --git a/testing/web-platform/tests/clear-site-data/support/test_utils.sub.js b/testing/web-platform/tests/clear-site-data/support/test_utils.sub.js
index 019d834d8e280..25333a87345b7 100644
--- a/testing/web-platform/tests/clear-site-data/support/test_utils.sub.js
+++ b/testing/web-platform/tests/clear-site-data/support/test_utils.sub.js
@@ -858,20 +858,6 @@ scope
 "
 support
 /
-scope
--
-that
--
-does
--
-not
--
-contain
--
-this
--
-test
-/
 "
 }
 )