https://chromium-review.googlesource.com/c/chromium/src/+/7790840
From: Matt Jolly <kangie@gentoo.org>
Date: Thu, 26 Feb 2026 15:44:57 +1000
Subject: [PATCH] chrome: Add enable_channel_branding GN flag for channel-aware
 builds

Add a new GN build flag `enable_channel_branding` (default:
is_chrome_branded) that allows non-Chrome-branded builds to use
channel-aware behavior: separate user data directories, desktop files,
and environment variable suffixes for beta, dev, and canary channels.

This benefits downstreams like Gentoo that support slotted packages,
enabling simultaneous installation of different channels with isolated
profile directories and protecting end users from unintentional
incompatible profile up/downgrades.

When disabled (the default for Chromium), behavior is unchanged.

Fixed: https://crbug.com/393183848
Signed-off-by: Matt Jolly <kangie@gentoo.org>
--- a/build/BUILD.gn
+++ b/build/BUILD.gn
@@ -33,6 +33,10 @@ buildflag_header("branding_buildflags") {
     ]
   }
 
+  flags += [
+    "ENABLE_CHANNEL_BRANDING=$enable_channel_branding",
+  ]
+
   if (is_chrome_for_testing) {
     assert(!is_chrome_branded,
            "`is_chrome_for_testing` is incompatible with `is_chrome_branded`")
--- a/build/config/chrome_build.gni
+++ b/build/config/chrome_build.gni
@@ -68,6 +68,11 @@ declare_args() {
   # Whether to apply size->speed trade-offs to the secondary toolchain.
   # Relevant only for 64-bit target_cpu.
   is_high_end_android_secondary_toolchain = false
+
+  # Enables channel branding. This is always true for Chrome branded builds,
+  # but can be optionally enabled for non-Chrome builds (e.g. Chromium) to
+  # allow "beta", "dev" channels with separate user data directories.
+  enable_channel_branding = is_chrome_branded
 }
 
 assert(!is_chrome_for_testing || !is_chrome_branded,
--- a/chrome/browser/ui/webui/current_channel_logo.cc
+++ b/chrome/browser/ui/webui/current_channel_logo.cc
@@ -29,7 +29,9 @@ int CurrentChannelLogoResourceId() {
     case version_info::Channel::DEV:
     case version_info::Channel::BETA:
     case version_info::Channel::STABLE:
+#if !BUILDFLAG(ENABLE_CHANNEL_BRANDING)
       CHECK_IS_TEST();
+#endif
       [[fallthrough]];
 #endif
     case version_info::Channel::UNKNOWN:
--- a/chrome/common/channel_info_posix.cc
+++ b/chrome/common/channel_info_posix.cc
@@ -27,23 +27,24 @@ struct ChannelState {
   bool is_extended_stable;
 };
 
-#if !BUILDFLAG(GOOGLE_CHROME_BRANDING)
+#if !BUILDFLAG(ENABLE_CHANNEL_BRANDING)
 std::string GetChannelEnv() {
   auto env = base::Environment::Create();
   std::optional<std::string> channel_env =
       env->GetVar(version_info::nix::kChromeVersionExtra);
   return channel_env.value_or(std::string());
 }
-#endif  // !BUILDFLAG(GOOGLE_CHROME_BRANDING)
+#endif  // !BUILDFLAG(ENABLE_CHANNEL_BRANDING)
 
 // Returns the channel state for the browser based on branding and the
 // CHROME_VERSION_EXTRA environment variable. In unbranded (Chromium) builds,
 // this function unconditionally returns `channel` = UNKNOWN and
-// `is_extended_stable` = false. In branded (Google Chrome) builds, this
-// function returns `channel` = UNKNOWN and `is_extended_stable` = false for any
+// `is_extended_stable` = false. In branded (Google Chrome or
+// enable_channel_branding=true) builds, this function returns
+// `channel` = UNKNOWN and `is_extended_stable` = false for any
 // unexpected $CHROME_VERSION_EXTRA value.
 ChannelState GetChannelImpl() {
-#if BUILDFLAG(GOOGLE_CHROME_BRANDING)
+#if BUILDFLAG(ENABLE_CHANNEL_BRANDING)
   auto env = base::Environment::Create();
   return {version_info::nix::GetChannel(*env),
           version_info::nix::IsExtendedStable(*env)};
@@ -55,11 +56,19 @@ ChannelState GetChannelImpl() {
 }  // namespace
 
 std::string GetChannelName(WithExtendedStable with_extended_stable) {
-#if BUILDFLAG(GOOGLE_CHROME_BRANDING)
+#if BUILDFLAG(ENABLE_CHANNEL_BRANDING)
   const auto channel_state = GetChannelImpl();
   switch (channel_state.channel) {
     case version_info::Channel::UNKNOWN:
+#if BUILDFLAG(GOOGLE_CHROME_BRANDING)
       return "unknown";
+#else
+    {
+      auto env = base::Environment::Create();
+      return env->GetVar(version_info::nix::kChromeVersionExtra)
+          .value_or(std::string());
+    }
+#endif
     case version_info::Channel::CANARY:
       return "canary";
     case version_info::Channel::DEV:
@@ -72,9 +81,9 @@ std::string GetChannelName(WithExtendedStable with_extended_stable) {
       }
       return std::string();
   }
-#else   // BUILDFLAG(GOOGLE_CHROME_BRANDING)
+#else   // BUILDFLAG(ENABLE_CHANNEL_BRANDING)
   return GetChannelEnv();
-#endif  // BUILDFLAG(GOOGLE_CHROME_BRANDING)
+#endif  // BUILDFLAG(ENABLE_CHANNEL_BRANDING)
 }
 
 std::string GetChannelSuffixForDataDir() {
@@ -94,7 +103,7 @@ std::string GetChannelSuffixForDataDir() {
 
 #if BUILDFLAG(IS_LINUX)
 std::string GetChannelSuffixForExtraFlagsEnvVarName() {
-#if BUILDFLAG(GOOGLE_CHROME_BRANDING)
+#if BUILDFLAG(ENABLE_CHANNEL_BRANDING)
   const auto channel_state = GetChannelImpl();
   switch (channel_state.channel) {
     case version_info::Channel::CANARY:
@@ -108,12 +117,12 @@ std::string GetChannelSuffixForExtraFlagsEnvVarName() {
     default:
       return std::string();
   }
-#else   // BUILDFLAG(GOOGLE_CHROME_BRANDING)
+#else   // BUILDFLAG(ENABLE_CHANNEL_BRANDING)
   std::string channel_name = GetChannelEnv();
   return channel_name.empty()
              ? std::string()
              : base::StrCat({"_", base::ToUpperASCII(channel_name)});
-#endif  // BUILDFLAG(GOOGLE_CHROME_BRANDING)
+#endif  // BUILDFLAG(ENABLE_CHANNEL_BRANDING)
 }
 #endif  // BUILDFLAG(IS_LINUX)
 
@@ -148,6 +157,18 @@ std::string GetDesktopName(base::Environment* env) {
   if (name.has_value() && !name.value().empty()) {
     return name.value();
   }
+#if BUILDFLAG(ENABLE_CHANNEL_BRANDING)
+  switch (GetChannel()) {
+    case version_info::Channel::CANARY:
+      return "chromium-browser-canary.desktop";
+    case version_info::Channel::DEV:
+      return "chromium-browser-unstable.desktop";
+    case version_info::Channel::BETA:
+      return "chromium-browser-beta.desktop";
+    default:
+      break;
+  }
+#endif
   return "chromium-browser.desktop";
 #endif
 }
-- 
2.53.0