Bug 2068538 - Remove the Legacy Telemetry mirrors of dom.webkit_directory_used and dom.blink_filesystem_used. r=smaug,dom-core-reviewers,janerik

These were added in bug 1272501 and are now recorded directly through Glean,
so the Legacy Telemetry mirror is no longer needed.

Differential Revision: https://phabricator.services.mozilla.com/D322884

dom/metrics.yaml

@@ -1170,9 +1170,6 @@ dom:
     type: labeled_counter
     description: >
       Webkit/Blink filesystem used
-
-      This metric was generated to correspond to the Legacy Telemetry boolean
-      histogram BLINK_FILESYSTEM_USED.
     labels:
       - "false"
       - "true"
@@ -1183,15 +1180,11 @@ dom:
     notification_emails:
       - amarchesini@mozilla.com
     expires: never
-    telemetry_mirror: h#BLINK_FILESYSTEM_USED
 
   webkit_directory_used:
     type: labeled_counter
     description: >
       HTMLInputElement.webkitdirectory attribute used
-
-      This metric was generated to correspond to the Legacy Telemetry boolean
-      histogram WEBKIT_DIRECTORY_USED.
     labels:
       - "false"
       - "true"
@@ -1202,4 +1195,3 @@ dom:
     notification_emails:
       - amarchesini@mozilla.com
     expires: never
-    telemetry_mirror: h#WEBKIT_DIRECTORY_USED

toolkit/components/telemetry/Histograms.json

@@ -3474,26 +3474,6 @@
     "releaseChannelCollection": "opt-out",
     "description": "Counts the number of times that about:tabcrashed was unloaded without submitting."
   },
-  "BLINK_FILESYSTEM_USED": {
-    "record_in_processes": ["main", "content"],
-    "products": ["firefox", "fennec"],
-    "alert_emails": ["amarchesini@mozilla.com"],
-    "expires_in_version": "never",
-    "kind": "boolean",
-    "bug_numbers": [1272501],
-    "releaseChannelCollection": "opt-out",
-    "description": "Webkit/Blink filesystem used"
-  },
-  "WEBKIT_DIRECTORY_USED": {
-    "record_in_processes": ["main", "content"],
-    "products": ["firefox", "fennec"],
-    "alert_emails": ["amarchesini@mozilla.com"],
-    "expires_in_version": "never",
-    "kind": "boolean",
-    "bug_numbers": [1272501],
-    "releaseChannelCollection": "opt-out",
-    "description": "HTMLInputElement.webkitdirectory attribute used"
-  },
   "PLACES_SEARCHBAR_FILTER_TYPE": {
     "record_in_processes": ["main"],
     "products": ["firefox"],