Rewrite is_linux flag for content and components directories.

This migrates is_linux (which is also set for chromeos) to explicitly
include chromeos as is_linux || is_chromeos in preparation for
separating those flags.

Bug: 1110266
Change-Id: I50f2e8769c8687a3c90d653010f2d92c7d70d0b8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2325769
Commit-Queue: Sean McAllister <smcallis@google.com>
Reviewed-by: Hidehiko Abe <hidehiko@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#793313}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 8ccdb76479df44f44e2b5974287bc11a5fd75dbb
diff --git a/BUILD.gn b/BUILD.gn
index f205f35..c18814d 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -400,7 +400,7 @@
   ]
 }
 
-if (is_linux) {
+if (is_linux || is_chromeos) {
   static_library("serialization") {
     sources = [
       "serialization/metric_sample.cc",
@@ -493,7 +493,7 @@
     ]
   }
 
-  if (is_linux) {
+  if (is_linux || is_chromeos) {
     sources += [ "serialization/serialization_utils_unittest.cc" ]
     deps += [ ":serialization" ]
   }