Move AlterEnvironment to base/environment.h, implement on Windows.

chrome/utility/importer/firefox_importer_unittest_utils_mac.cc

Index: chrome/utility/importer/firefox_importer_unittest_utils_mac.cc
diff --git a/chrome/utility/importer/firefox_importer_unittest_utils_mac.cc b/chrome/utility/importer/firefox_importer_unittest_utils_mac.cc
index 5e8cb9d305d10977150afd37a11d0a03b72df16e..cbbf5a94b265271802bcdd3e04b6550cb45f741c 100644
--- a/chrome/utility/importer/firefox_importer_unittest_utils_mac.cc
+++ b/chrome/utility/importer/firefox_importer_unittest_utils_mac.cc
@@ -43,11 +43,8 @@ bool LaunchNSSDecrypterChildProcess(const base::FilePath& nss_path,
   // Set env variable needed for FF encryption libs to load.
   // See "chrome/utility/importer/nss_decryptor_mac.mm" for an explanation of
   // why we need this.
-  base::EnvironmentVector env;
-  std::pair<std::string, std::string> dyld_override;
-  dyld_override.first = "DYLD_FALLBACK_LIBRARY_PATH";
-  dyld_override.second = nss_path.value();
-  env.push_back(dyld_override);
+  base::LaunchOptions options;
+  options.environ["DYLD_FALLBACK_LIBRARY_PATH"] = nss_path.value();
 
   int ipcfd = channel->TakeClientFileDescriptor();
   if (ipcfd == -1)
@@ -59,8 +56,6 @@ bool LaunchNSSDecrypterChildProcess(const base::FilePath& nss_path,
 
   bool debug_on_start = CommandLine::ForCurrentProcess()->HasSwitch(
                             switches::kDebugChildren);
-  base::LaunchOptions options;
-  options.environ = &env;
   options.fds_to_remap = &fds_to_map;
   options.wait = debug_on_start;
   return base::LaunchProcess(cl.argv(), options, handle);