Capture a report on failed browser rendez-vous.

third_party/kasko/BUILD.gn

Index: third_party/kasko/BUILD.gn
diff --git a/third_party/kasko/BUILD.gn b/third_party/kasko/BUILD.gn
index 2d06fe09a8d763498a9b9f99e5aaed757fd3c705..c472e9024b329773854228d0ddef76a3e514382e 100644
--- a/third_party/kasko/BUILD.gn
+++ b/third_party/kasko/BUILD.gn
@@ -11,6 +11,9 @@ declare_args() {
 
   # Enable the reporting of browser hangs with Kasko.
   enable_kasko_hang_reports = false
+
+  # Enable the reporting of failed browser rendez-vous with Kasko.
+  enable_kasko_failed_rdv_reports = false
 }
 
 # GYP version: target 'kasko_features' in third_party/kasko/kasko.gyp
@@ -19,6 +22,7 @@ buildflag_header("kasko_features") {
   flags = [
     "ENABLE_KASKO=$enable_kasko",
     "ENABLE_KASKO_HANG_REPORTS=$enable_kasko_hang_reports",
+    "ENABLE_KASKO_FAILED_RDV_REPORTS=$enable_kasko_failed_rdv_reports",
   ]
 }