From 1e85e4281a3bdcb5b632444902c1093d57324757 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Florian=20Qu=C3=A8ze?= <florian@queze.net>
Date: Wed, 2 Oct 2024 21:05:57 +0000
Subject: [PATCH] Bug 1922231 - Avoid recording to histograms or scalars in
 processes that don't match the probe definition, r=chutten.

Differential Revision: https://phabricator.services.mozilla.com/D224309
---
 layout/style/PreferenceSheet.cpp               | 5 +++++
 toolkit/components/startup/StartupTimeline.cpp | 6 +++++-
 uriloader/preload/PreloaderBase.cpp            | 2 +-
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/layout/style/PreferenceSheet.cpp b/layout/style/PreferenceSheet.cpp
index 8b0179a02911..e1d05228225b 100644
--- a/layout/style/PreferenceSheet.cpp
+++ b/layout/style/PreferenceSheet.cpp
@@ -270,6 +270,11 @@ void PreferenceSheet::Initialize() {
     }
   }
 
+  // Telemetry for these preferences is only collected on the parent process.
+  if (!XRE_IsParentProcess()) {
+    return;
+  }
+
   nsAutoString useDocumentColorPref;
   switch (StaticPrefs::browser_display_document_color_use()) {
     case 1:
diff --git a/toolkit/components/startup/StartupTimeline.cpp b/toolkit/components/startup/StartupTimeline.cpp
index 689437b0432a..7c70e8504751 100644
--- a/toolkit/components/startup/StartupTimeline.cpp
+++ b/toolkit/components/startup/StartupTimeline.cpp
@@ -43,7 +43,11 @@ void StartupTimeline::RecordOnce(Event ev, const TimeStamp& aWhen) {
 
   Record(ev, aWhen);
 
-  // Record first paint timestamp as a scalar.
+  // Record first paint timestamp as a scalar in the parent process.
+  if (!XRE_IsParentProcess()) {
+    return;
+  }
+
   if (ev == FIRST_PAINT || ev == FIRST_PAINT2) {
     uint32_t firstPaintTime =
         (uint32_t)(aWhen - TimeStamp::ProcessCreation()).ToMilliseconds();
diff --git a/uriloader/preload/PreloaderBase.cpp b/uriloader/preload/PreloaderBase.cpp
index e8b2889cf6a6..1609573dd88b 100644
--- a/uriloader/preload/PreloaderBase.cpp
+++ b/uriloader/preload/PreloaderBase.cpp
@@ -305,7 +305,7 @@ void PreloaderBase::CancelUsageTimer() {
 }
 
 void PreloaderBase::ReportUsageTelemetry() {
-  if (mUsageTelementryReported) {
+  if (mUsageTelementryReported || !XRE_IsContentProcess()) {
     return;
   }
   mUsageTelementryReported = true;