[remoting] Modernize Environment::GetVar to use std::optional

Updates GetVar usage to use the modern std::optional API
instead of out-parameters.

Bug: 400758498

Change-Id: I88e21dd3b21f709722a348ca55f5f070c8951f79
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6426204
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Colin Blundell <blundell@chromium.org>
Reviewed-by: Joe Downing <joedow@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1443592}

media/gpu/vaapi/test/fake_libva_driver/fake_context.cc

@@ -21,9 +21,9 @@ std::unique_ptr<media::internal::ContextDelegate> CreateDelegate(
     int picture_height) {
   std::unique_ptr<base::Environment> env = base::Environment::Create();
   CHECK(env);
-  std::string no_op_flag;
-  if (env->GetVar("USE_NO_OP_CONTEXT_DELEGATE", &no_op_flag) &&
-      no_op_flag == "1") {
+  std::string no_op_flag =
+      env->GetVar("USE_NO_OP_CONTEXT_DELEGATE").value_or(std::string());
+  if (no_op_flag == "1") {
     return std::make_unique<media::internal::NoOpContextDelegate>();
   }
 

pdf/pdfium/pdfium_test_base.cc

@@ -34,9 +34,9 @@ namespace {
 base::FilePath GetTestFontsDir() {
   // base::TestSuite::Initialize() should have already set this.
   std::unique_ptr<base::Environment> env(base::Environment::Create());
-  std::string fontconfig_sysroot;
-  CHECK(env->GetVar("FONTCONFIG_SYSROOT", &fontconfig_sysroot));
-  return base::FilePath(fontconfig_sysroot).AppendASCII("test_fonts");
+  auto fontconfig_sysroot = env->GetVar("FONTCONFIG_SYSROOT");
+  CHECK(fontconfig_sysroot.has_value());
+  return base::FilePath(fontconfig_sysroot.value()).AppendASCII("test_fonts");
 }
 #endif  // BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)
 

remoting/host/remote_open_url/remote_open_url_client_delegate_linux.cc

@@ -114,8 +114,8 @@ RemoteOpenUrlClientDelegateLinux::~RemoteOpenUrlClientDelegateLinux() = default;
 
 void RemoteOpenUrlClientDelegateLinux::OpenUrlOnFallbackBrowser(
     const GURL& url) {
-  std::string current_desktop;
-  environment_->GetVar(kXdgCurrentDesktopEnvVar, &current_desktop);
+  std::string current_desktop =
+      environment_->GetVar(kXdgCurrentDesktopEnvVar).value_or(std::string());
 
   const char* host_setting_key = kLinuxPreviousDefaultWebBrowserGeneric;
   if (base::Contains(current_desktop, "Cinnamon")) {

remoting/host/webauthn/remote_webauthn_caller_security_utils.cc

@@ -4,6 +4,7 @@
 
 #include "remoting/host/webauthn/remote_webauthn_caller_security_utils.h"
 
+#include <optional>
 #include <string_view>
 
 #include "base/environment.h"
@@ -108,9 +109,9 @@ bool IsLaunchedByTrustedProcess() {
 
   // COMSPEC is generally "C:\WINDOWS\system32\cmd.exe". Note that the casing
   // does not match the actual file path's casing.
-  std::string comspec_utf8;
-  if (environment->GetVar("COMSPEC", &comspec_utf8)) {
-    base::FilePath::StringType comspec = base::UTF8ToWide(comspec_utf8);
+  std::optional<std::string> comspec_utf8 = environment->GetVar("COMSPEC");
+  if (comspec_utf8.has_value()) {
+    base::FilePath::StringType comspec = base::UTF8ToWide(comspec_utf8.value());
     if (base::FilePath::CompareEqualIgnoreCase(parent_image_path.value(),
                                                comspec)) {
       // Skip to the grandparent.
@@ -129,11 +130,13 @@ bool IsLaunchedByTrustedProcess() {
 
   // Check if the caller's image path is allowlisted.
   for (std::string_view apps_dir_env_var : kAppsDirectoryEnvVars) {
-    std::string apps_dir_path_utf8;
-    if (!environment->GetVar(apps_dir_env_var, &apps_dir_path_utf8)) {
+    std::optional<std::string> apps_dir_path_utf8 =
+        environment->GetVar(apps_dir_env_var);
+    if (!apps_dir_path_utf8.has_value()) {
       continue;
     }
-    auto apps_dir_path = base::FilePath::FromUTF8Unsafe(apps_dir_path_utf8);
+    auto apps_dir_path =
+        base::FilePath::FromUTF8Unsafe(apps_dir_path_utf8.value());
     if (!apps_dir_path.IsParent(parent_image_path)) {
       continue;
     }

remoting/host/webauthn/remote_webauthn_extension_notifier.cc

@@ -9,6 +9,7 @@
 
 #include "remoting/host/webauthn/remote_webauthn_extension_notifier.h"
 
+#include <optional>
 #include <vector>
 
 #include "base/base_paths.h"
@@ -86,10 +87,11 @@ std::vector<base::FilePath> GetRemoteStateChangeDirPaths() {
   // See: chrome/common/chrome_paths_linux.cc
   auto env = base::Environment::Create();
   base::FilePath base_path;
-  std::string chrome_config_home_str;
-  if (env->GetVar("CHROME_CONFIG_HOME", &chrome_config_home_str) &&
-      base::IsStringUTF8(chrome_config_home_str)) {
-    base_path = base::FilePath::FromUTF8Unsafe(chrome_config_home_str);
+  std::optional<std::string> chrome_config_home_str =
+      env->GetVar("CHROME_CONFIG_HOME");
+  if (chrome_config_home_str.has_value() &&
+      base::IsStringUTF8(chrome_config_home_str.value())) {
+    base_path = base::FilePath::FromUTF8Unsafe(chrome_config_home_str.value());
   } else {
     base_path = base::nix::GetXDGDirectory(
         env.get(), base::nix::kXdgConfigHomeEnvVar, base::nix::kDotConfigDir);