Bug 1356181 - Gather telemetry about isindex usage in hope of justifying removal. r=Ehsan,francois

MozReview-Commit-ID: 9dDVvgxxZml

--HG--
extra : rebase_source : c78e97a5b1bcd1d322ba1381657ed9bd3e814f11

dom/html/HTMLFormSubmission.cpp

@@ -35,6 +35,7 @@
 #include "nsCExternalHandlerService.h"
 #include "nsIFileStreams.h"
 #include "nsContentUtils.h"
+#include "mozilla/Telemetry.h"
 
 #include "mozilla/dom/Directory.h"
 #include "mozilla/dom/EncodingUtils.h"
@@ -188,6 +189,7 @@ FSURLEncoded::AddIsindex(const nsAString& aValue)
 
   // Append data to string
   if (mQueryString.IsEmpty()) {
+    Telemetry::Accumulate(Telemetry::FORM_ISINDEX_USED, true);
     mQueryString.Assign(convValue);
   } else {
     mQueryString += NS_LITERAL_CSTRING("&isindex=") + convValue;

toolkit/components/telemetry/Histograms.json

@@ -5917,6 +5917,13 @@
     "kind": "boolean",
     "description": "Deleted or to-be-reused innerwindow which has had mutation event listeners."
   },
+  "FORM_ISINDEX_USED": {
+    "alert_emails": ["hsivonen@mozilla.com"],
+    "expires_in_version": "56",
+    "kind": "flag",
+    "bug_numbers": [1356181],
+    "description": "Whether there has been an isindex form submission in this session."
+  },
   "CHARSET_OVERRIDE_SITUATION": {
     "expires_in_version": "never",
     "kind": "enumerated",

toolkit/components/telemetry/histogram-whitelists.json

@@ -1981,6 +1981,7 @@
     "FX_TOUCH_USED",
     "GEOLOCATION_ERROR",
     "JS_TELEMETRY_ADDON_EXCEPTIONS",
+    "FORM_ISINDEX_USED",
     "MASTER_PASSWORD_ENABLED",
     "MEDIA_CODEC_USED",
     "MEDIA_DECODING_PROCESS_CRASH",