Fuchsia: Prepare for OS_POSIX removal in base/

This cleans up multi-platform code paths selection and prepares for
the removal of OS_POSIX for the Fuchsia build.

Bug: 836416
Change-Id: I3a8e6393d0a9981aa890fb6d8c302ed8d2bdd69d
Reviewed-on: https://chromium-review.googlesource.com/1031099
Commit-Queue: Fabrice de Gans-Riberi <[email protected]>
Reviewed-by: Kinuko Yasuda <[email protected]>
Reviewed-by: Nico Weber <[email protected]>
Cr-Commit-Position: refs/heads/master@{#559230}
diff --git a/base/command_line_unittest.cc b/base/command_line_unittest.cc
index 6785350..3718cd9 100644
--- a/base/command_line_unittest.cc
+++ b/base/command_line_unittest.cc
@@ -208,7 +208,7 @@
   CommandLine::StringType expected_third_arg(UTF8ToUTF16(kThirdArgName));
   CommandLine::StringType expected_fourth_arg(UTF8ToUTF16(kFourthArgName));
   CommandLine::StringType expected_fifth_arg(UTF8ToUTF16(kFifthArgName));
-#elif defined(OS_POSIX)
+#elif defined(OS_POSIX) || defined(OS_FUCHSIA)
   CommandLine::StringType expected_first_arg(kFirstArgName);
   CommandLine::StringType expected_second_arg(kSecondArgName);
   CommandLine::StringType expected_third_arg(kThirdArgName);