Added finch control SendWebUIJavaScriptErrorReports

This will control a feature which will send reports if the JavaScript on
a WebUI surface has a serious error, such as an unhandled exception.

Following instruction from go/finch-feature-api

Launch bug: https://crbug.com/1134416

Bug: chromium:1121816
Change-Id: Iaf2ac7935bf0546a9d1cc3709448ab5695b62196
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2462487
Reviewed-by: Kinuko Yasuda <[email protected]>
Commit-Queue: Ian Barkley-Yeung <[email protected]>
Cr-Commit-Position: refs/heads/master@{#816621}
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 6e937c88..50cdaf3 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -2335,6 +2335,20 @@
 constexpr char kAmbientModeInternalName[] = "enable-ambient-mode";
 #endif  // OS_CHROMEOS
 
+#if !defined(OS_WIN) && !defined(OS_FUCHSIA)
+const FeatureEntry::FeatureParam
+    kSendWebUIJavaScriptErrorReportsVariationSendToStaging[] = {
+        {features::kSendWebUIJavaScriptErrorReportsSendToProductionVariation,
+         "false"}};
+
+const FeatureEntry::FeatureVariation
+    kSendWebUIJavaScriptErrorReportsVariations[] = {
+        {"Send reports to staging server.",
+         kSendWebUIJavaScriptErrorReportsVariationSendToStaging,
+         base::size(kSendWebUIJavaScriptErrorReportsVariationSendToStaging),
+         nullptr}};
+#endif
+
 #if defined(OS_ANDROID)
 // The variations of --metrics-settings-android.
 const FeatureEntry::FeatureParam kMetricsSettingsAndroidAlternativeOne[] = {
@@ -2442,6 +2456,16 @@
      flag_descriptions::kWebrtcPipeWireCapturerDescription, kOsLinux,
      FEATURE_VALUE_TYPE(features::kWebRtcPipeWireCapturer)},
 #endif  // defined(WEBRTC_USE_PIPEWIRE)
+#if !defined(OS_WIN) && !defined(OS_FUCHSIA)
+    {"send-webui-javascript-error-reports",
+     flag_descriptions::kSendWebUIJavaScriptErrorReportsName,
+     flag_descriptions::kSendWebUIJavaScriptErrorReportsDescription,
+     kOsLinux | kOsCrOS | kOsAndroid,
+     FEATURE_WITH_PARAMS_VALUE_TYPE(
+         features::kSendWebUIJavaScriptErrorReports,
+         kSendWebUIJavaScriptErrorReportsVariations,
+         "SendWebUIJavaScriptErrorReportsVariations")},
+#endif
 #if !defined(OS_ANDROID)
     {"enable-webrtc-remote-event-log",
      flag_descriptions::kWebRtcRemoteEventLogName,