diff --git a/client/BUILD.gn b/client/BUILD.gn
index bd150ab9..16838df8 100644
--- a/client/BUILD.gn
+++ b/client/BUILD.gn
@@ -79,10 +79,7 @@ crashpad_static_library("client") {
     "../util",
   ]
 
-  deps = [
-    ":common",
-    "$mini_chromium_source_parent:chromeos_buildflags",
-  ]
+  deps = [ ":common" ]
 
   if (crashpad_is_win) {
     libs = [ "rpcrt4.lib" ]
diff --git a/client/crashpad_client.h b/client/crashpad_client.h
index 6872d1f3..41f03211 100644
--- a/client/crashpad_client.h
+++ b/client/crashpad_client.h
@@ -25,7 +25,6 @@
 
 #include "base/files/file_path.h"
 #include "build/build_config.h"
-#include "build/chromeos_buildflags.h"
 #include "util/file/file_io.h"
 
 #if !BUILDFLAG(IS_FUCHSIA)
@@ -799,7 +798,7 @@ class CrashpadClient {
   static void UseSystemDefaultHandler();
 #endif
 
-#if BUILDFLAG(IS_CHROMEOS_ASH)
+#if BUILDFLAG(IS_CHROMEOS)
   //! \brief Sets a timestamp on the signal handler to be passed on to
   //!     crashpad_handler and then eventually Chrome OS's crash_reporter.
   //!
diff --git a/client/crashpad_client_linux.cc b/client/crashpad_client_linux.cc
index 1d79be7a..8241d23a 100644
--- a/client/crashpad_client_linux.cc
+++ b/client/crashpad_client_linux.cc
@@ -34,7 +34,6 @@
 #include "base/logging.h"
 #include "base/strings/stringprintf.h"
 #include "build/build_config.h"
-#include "build/chromeos_buildflags.h"
 #include "client/client_argv_handling.h"
 #include "third_party/lss/lss.h"
 #include "util/file/file_io.h"
@@ -406,7 +405,7 @@ class RequestCrashDumpHandler : public SignalHandler {
     ExceptionHandlerProtocol::ClientInformation info = {};
     info.exception_information_address =
         FromPointerCast<VMAddress>(&GetExceptionInfo());
-#if BUILDFLAG(IS_CHROMEOS_ASH)
+#if BUILDFLAG(IS_CHROMEOS)
     info.crash_loop_before_time = crash_loop_before_time_;
 #endif
 
@@ -414,7 +413,7 @@ class RequestCrashDumpHandler : public SignalHandler {
     client.RequestCrashDump(info);
   }
 
-#if BUILDFLAG(IS_CHROMEOS_ASH)
+#if BUILDFLAG(IS_CHROMEOS)
   void SetCrashLoopBefore(uint64_t crash_loop_before_time) {
     crash_loop_before_time_ = crash_loop_before_time;
   }
@@ -436,7 +435,7 @@ class RequestCrashDumpHandler : public SignalHandler {
   ScopedFileHandle sock_to_handler_;
   pid_t handler_pid_ = -1;
 
-#if BUILDFLAG(IS_CHROMEOS_ASH)
+#if BUILDFLAG(IS_CHROMEOS)
   // An optional UNIX timestamp passed to us from Chrome.
   // This will pass to crashpad_handler and then to Chrome OS crash_reporter.
   // This should really be a time_t, but it's basically an opaque value (we
@@ -763,7 +762,7 @@ void CrashpadClient::SetUnhandledSignals(const std::set<int>& signals) {
   unhandled_signals_ = signals;
 }
 
-#if BUILDFLAG(IS_CHROMEOS_ASH)
+#if BUILDFLAG(IS_CHROMEOS)
 // static
 void CrashpadClient::SetCrashLoopBefore(uint64_t crash_loop_before_time) {
   auto request_crash_dump_handler = RequestCrashDumpHandler::Get();
diff --git a/handler/BUILD.gn b/handler/BUILD.gn
index 104e8502..368fef05 100644
--- a/handler/BUILD.gn
+++ b/handler/BUILD.gn
@@ -74,7 +74,6 @@ static_library("handler") {
     ":common",
     "../minidump",
     "../snapshot",
-    "../third_party/mini_chromium:chromeos_buildflags",
     "../tools:tool_support",
   ]
 
diff --git a/handler/handler_main.cc b/handler/handler_main.cc
index 7e908c0a..6eca8415 100644
--- a/handler/handler_main.cc
+++ b/handler/handler_main.cc
@@ -38,7 +38,6 @@
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "build/build_config.h"
-#include "build/chromeos_buildflags.h"
 #include "client/crash_report_database.h"
 #include "client/crashpad_client.h"
 #include "client/crashpad_info.h"
@@ -57,7 +56,7 @@
 #include "util/string/split_string.h"
 #include "util/synchronization/semaphore.h"
 
-#if BUILDFLAG(IS_CHROMEOS_ASH) || BUILDFLAG(IS_CHROMEOS_LACROS)
+#if BUILDFLAG(IS_CHROMEOS)
 #include "handler/linux/cros_crash_report_exception_handler.h"
 #endif
 
@@ -192,7 +191,7 @@ void Usage(const base::FilePath& me) {
 "      --url=URL               send crash reports to this Breakpad server URL,\n"
 "                              only if uploads are enabled for the database\n"
   // clang-format on
-#if BUILDFLAG(IS_CHROMEOS_ASH) || BUILDFLAG(IS_CHROMEOS_LACROS)
+#if BUILDFLAG(IS_CHROMEOS)
       // clang-format off
 "      --use-cros-crash-reporter\n"
 "                              pass crash reports to /sbin/crash_reporter\n"
@@ -205,7 +204,7 @@ void Usage(const base::FilePath& me) {
 "                              crash_reporter, thus skipping metrics consent\n"
 "                              checks\n"
   // clang-format on
-#endif  // BUILDFLAG(IS_CHROMEOS_ASH) || BUILDFLAG(IS_CHROMEOS_LACROS)
+#endif  // BUILDFLAG(IS_CHROMEOS)
 #if BUILDFLAG(IS_ANDROID)
       // clang-format off
 "      --write-minidump-to-log write minidump to log\n"
@@ -248,11 +247,11 @@ struct Options {
   bool periodic_tasks;
   bool rate_limit;
   bool upload_gzip;
-#if BUILDFLAG(IS_CHROMEOS_ASH) || BUILDFLAG(IS_CHROMEOS_LACROS)
+#if BUILDFLAG(IS_CHROMEOS)
   bool use_cros_crash_reporter = false;
   base::FilePath minidump_dir_for_tests;
   bool always_allow_feedback = false;
-#endif  // BUILDFLAG(IS_CHROMEOS_ASH) || BUILDFLAG(IS_CHROMEOS_LACROS)
+#endif  // BUILDFLAG(IS_CHROMEOS)
 #if defined(ATTACHMENTS_SUPPORTED)
   std::vector<base::FilePath> attachments;
 #endif  // ATTACHMENTS_SUPPORTED
@@ -551,7 +550,7 @@ class ScopedStoppable {
 
 void InitCrashpadLogging() {
   logging::LoggingSettings settings;
-#if BUILDFLAG(IS_CHROMEOS_ASH)
+#if BUILDFLAG(IS_CHROMEOS)
   settings.logging_dest = logging::LOG_TO_FILE;
   settings.log_file_path = "/var/log/chrome/chrome";
 #elif BUILDFLAG(IS_WIN)
@@ -622,11 +621,11 @@ int HandlerMain(int argc,
     kOptionTraceParentWithException,
 #endif
     kOptionURL,
-#if BUILDFLAG(IS_CHROMEOS_ASH) || BUILDFLAG(IS_CHROMEOS_LACROS)
+#if BUILDFLAG(IS_CHROMEOS)
     kOptionUseCrosCrashReporter,
     kOptionMinidumpDirForTests,
     kOptionAlwaysAllowFeedback,
-#endif  // BUILDFLAG(IS_CHROMEOS_ASH) || BUILDFLAG(IS_CHROMEOS_LACROS)
+#endif  // BUILDFLAG(IS_CHROMEOS)
 #if BUILDFLAG(IS_ANDROID)
     kOptionWriteMinidumpToLog,
 #endif  // BUILDFLAG(IS_ANDROID)
@@ -706,7 +705,7 @@ int HandlerMain(int argc,
 #endif  // BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) ||
         // BUILDFLAG(IS_ANDROID)
     {"url", required_argument, nullptr, kOptionURL},
-#if BUILDFLAG(IS_CHROMEOS_ASH) || BUILDFLAG(IS_CHROMEOS_LACROS)
+#if BUILDFLAG(IS_CHROMEOS)
     {"use-cros-crash-reporter",
      no_argument,
      nullptr,
@@ -716,7 +715,7 @@ int HandlerMain(int argc,
      nullptr,
      kOptionMinidumpDirForTests},
     {"always-allow-feedback", no_argument, nullptr, kOptionAlwaysAllowFeedback},
-#endif  // BUILDFLAG(IS_CHROMEOS_ASH) || BUILDFLAG(IS_CHROMEOS_LACROS)
+#endif  // BUILDFLAG(IS_CHROMEOS)
 #if BUILDFLAG(IS_ANDROID)
     {"write-minidump-to-log", no_argument, nullptr, kOptionWriteMinidumpToLog},
 #endif  // BUILDFLAG(IS_ANDROID)
@@ -879,7 +878,7 @@ int HandlerMain(int argc,
         options.url = optarg;
         break;
       }
-#if BUILDFLAG(IS_CHROMEOS_ASH) || BUILDFLAG(IS_CHROMEOS_LACROS)
+#if BUILDFLAG(IS_CHROMEOS)
       case kOptionUseCrosCrashReporter: {
         options.use_cros_crash_reporter = true;
         break;
@@ -893,7 +892,7 @@ int HandlerMain(int argc,
         options.always_allow_feedback = true;
         break;
       }
-#endif  // BUILDFLAG(IS_CHROMEOS_ASH) || BUILDFLAG(IS_CHROMEOS_LACROS)
+#endif  // BUILDFLAG(IS_CHROMEOS)
 #if BUILDFLAG(IS_ANDROID)
       case kOptionWriteMinidumpToLog: {
         options.write_minidump_to_log = true;
@@ -1042,7 +1041,7 @@ int HandlerMain(int argc,
   std::unique_ptr<CrashReportExceptionHandler> exception_handler;
 #endif
 
-#if BUILDFLAG(IS_CHROMEOS_ASH) || BUILDFLAG(IS_CHROMEOS_LACROS)
+#if BUILDFLAG(IS_CHROMEOS)
   if (options.use_cros_crash_reporter) {
     auto cros_handler = std::make_unique<CrosCrashReportExceptionHandler>(
         database.get(),
@@ -1085,7 +1084,7 @@ int HandlerMain(int argc,
       false,
 #endif  // BUILDFLAG(IS_LINUX)
       user_stream_sources);
-#endif  // BUILDFLAG(IS_CHROMEOS_ASH) || BUILDFLAG(IS_CHROMEOS_LACROS)
+#endif  // BUILDFLAG(IS_CHROMEOS)
 
 #if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_ANDROID)
   if (options.exception_information_address) {
diff --git a/handler/linux/cros_crash_report_exception_handler.cc b/handler/linux/cros_crash_report_exception_handler.cc
index 25637408..51486a10 100644
--- a/handler/linux/cros_crash_report_exception_handler.cc
+++ b/handler/linux/cros_crash_report_exception_handler.cc
@@ -257,8 +257,6 @@ bool CrosCrashReportExceptionHandler::HandleExceptionWithConnection(
   constexpr int32_t kFixedVersion = 15363;
   // TODO(https://crbug.com/1420445): Remove this check (and the
   // CRASHPAD_IS_IN_CHROMIUM defines) when M115 branches.
-  // (Lacros is guaranteed not to be more than 2 milestones ahead of ash, and
-  // M113 on ash has the relevant crash_reporter change.)
   if (major_version >= kFixedVersion) {
     // Used to distinguish between non-fatal and fatal crashes.
     const ExceptionSnapshot* const exception_snapshot = snapshot->Exception();
diff --git a/third_party/mini_chromium/BUILD.gn b/third_party/mini_chromium/BUILD.gn
index 9d4ff01c..61a60ffa 100644
--- a/third_party/mini_chromium/BUILD.gn
+++ b/third_party/mini_chromium/BUILD.gn
@@ -49,17 +49,3 @@ group("build") {
     public_deps = [ "//third_party/mini_chromium/mini_chromium/build" ]
   }
 }
-
-group("chromeos_buildflags") {
-  if (crashpad_is_in_chromium) {
-    public_deps = [ "//build:chromeos_buildflags" ]
-  } else if (crashpad_is_standalone) {
-    public_deps = [ "mini_chromium/build:chromeos_buildflags" ]
-  } else if (crashpad_is_in_fuchsia) {
-    public_deps = [ mini_chromium_import_root + "/build:chromeos_buildflags" ]
-  } else if (crashpad_is_external) {
-    public_deps = [ "../../../../mini_chromium/mini_chromium/build:chromeos_buildflags" ]
-  } else if (crashpad_is_in_dart) {
-    public_deps = [ "//third_party/mini_chromium/mini_chromium/build:chromeos_buildflags" ]
-  }
-}
diff --git a/util/BUILD.gn b/util/BUILD.gn
index 8d037fea..ea2e95c7 100644
--- a/util/BUILD.gn
+++ b/util/BUILD.gn
@@ -573,10 +573,7 @@ crashpad_static_library("util") {
     "../third_party/zlib",
   ]
 
-  deps += [
-    "$mini_chromium_source_parent:base",
-    "$mini_chromium_source_parent:chromeos_buildflags",
-  ]
+  deps = [ "$mini_chromium_source_parent:base" ]
 
   configs = [ "../build:flock_always_supported_defines" ]
 
diff --git a/util/posix/scoped_mmap.cc b/util/posix/scoped_mmap.cc
index b9b42480..ee76c856 100644
--- a/util/posix/scoped_mmap.cc
+++ b/util/posix/scoped_mmap.cc
@@ -24,19 +24,14 @@
 #include "base/numerics/safe_conversions.h"
 #include "base/numerics/safe_math.h"
 #include "build/build_config.h"
-#include "build/chromeos_buildflags.h"
 
-// TODO(crbug.com/1052397): Revisit once build flag switch of lacros-chrome is
-// complete.
-#if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS_LACROS)
+#if BUILDFLAG(IS_LINUX)
 #include "third_party/lss/lss.h"
 #endif
 
 namespace {
 
-// TODO(crbug.com/1052397): Revisit once build flag switch of lacros-chrome is
-// complete.
-#if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS_LACROS)
+#if BUILDFLAG(IS_LINUX)
 void* CallMmap(void* addr,
                size_t len,
                int prot,