[Background Fetch] Update Webview expectations.

Bug: 766077
Change-Id: Ie52fc2eea6e96580bb064ac3b9c877a0ef96ff2a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1508466Reviewed-by: Tim Volodine <timvolodine@chromium.org>
Commit-Queue: Mugdha Lakhani <nator@chromium.org>
Cr-Commit-Position: refs/heads/master@{#638633}

android_webview/tools/system_webview_shell/test/data/webexposed/not-webview-exposed.txt

@@ -107,6 +107,31 @@ interface HTMLVideoElement : HTMLMediaElement
     getter onleavepictureinpicture
     setter onleavepictureinpicture
 
+# Background Fetch API is not enabled in Android webview, crbug.com/766077
+interface BackgroundFetchManager
+    method fetch
+    method get
+    method getIds
+interface BackgroundFetchRecord
+    getter request
+    getter responseReady
+interface BackgroundFetchRegistration : EventTarget
+    getter downloadTotal
+    getter downloaded
+    getter failureReason
+    getter id
+    getter onprogress
+    getter recordsAvailable
+    getter result
+    getter uploadTotal
+    getter uploaded
+    method abort
+    method match
+    method matchAll
+    setter onprogress
+interface ServiceWorkerRegistration : EventTarget
+    getter backgroundFetch
+
 # support_webgl2_compute_context not supported on android, crbug.com/865569
 interface WebGL2ComputeRenderingContext