Expand is_linux to is_linux || is_chromeos.

Currently is_linux is set to true on Chrome OS build,
but it is planned to be set false. This CL is the preparation
to keep the compatibility.

Bug: chromium:1110266
Test: Build locally.
Change-Id: Ic79a202b0b3baeff157955cd03a07556bfb958a8
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/183860
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Hidehiko Abe <hidehiko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#32073}
diff --git a/modules/audio_coding/BUILD.gn b/modules/audio_coding/BUILD.gn
index 5579539..3354033 100644
--- a/modules/audio_coding/BUILD.gn
+++ b/modules/audio_coding/BUILD.gn
@@ -483,7 +483,7 @@
     "codecs/isac/main/source/transform.c",
   ]
 
-  if (is_linux) {
+  if (is_linux || is_chromeos) {
     libs = [ "m" ]
   }
 
diff --git a/modules/audio_device/BUILD.gn b/modules/audio_device/BUILD.gn
index d610639..819a866 100644
--- a/modules/audio_device/BUILD.gn
+++ b/modules/audio_device/BUILD.gn
@@ -263,7 +263,7 @@
     if (rtc_use_dummy_audio_file_devices) {
       defines += [ "WEBRTC_DUMMY_FILE_DEVICES" ]
     } else {
-      if (is_linux) {
+      if (is_linux || is_chromeos) {
         sources += [
           "linux/alsasymboltable_linux.cc",
           "linux/alsasymboltable_linux.h",
@@ -393,7 +393,7 @@
       "../utility",
     ]
     absl_deps = [ "//third_party/abseil-cpp/absl/types:optional" ]
-    if (is_linux || is_mac || is_win) {
+    if (is_linux || is_chromeos || is_mac || is_win) {
       sources += [ "audio_device_unittest.cc" ]
     }
     if (is_win) {
diff --git a/modules/desktop_capture/BUILD.gn b/modules/desktop_capture/BUILD.gn
index 1cba946..eb57a46 100644
--- a/modules/desktop_capture/BUILD.gn
+++ b/modules/desktop_capture/BUILD.gn
@@ -140,7 +140,7 @@
       "screen_drawer.h",
     ]
 
-    if (is_linux) {
+    if (is_linux || is_chromeos) {
       sources += [ "screen_drawer_linux.cc" ]
     }
 
@@ -186,7 +186,7 @@
   }
 }
 
-if (is_linux) {
+if (is_linux || is_chromeos) {
   if (rtc_use_pipewire) {
     pkg_config("gio") {
       packages = [
@@ -357,7 +357,7 @@
       "window_capturer_linux.cc",
     ]
 
-    if (build_with_mozilla && is_linux) {
+    if (build_with_mozilla && (is_linux || is_chromeos)) {
       sources += [
         "app_capturer_linux.cc",
         "linux/app_capturer_x11.cc",
diff --git a/modules/video_capture/BUILD.gn b/modules/video_capture/BUILD.gn
index 741d6e2..9822981 100644
--- a/modules/video_capture/BUILD.gn
+++ b/modules/video_capture/BUILD.gn
@@ -56,7 +56,7 @@
       "../../system_wrappers",
     ]
 
-    if (is_linux) {
+    if (is_linux || is_chromeos) {
       sources = [
         "linux/device_info_linux.cc",
         "linux/device_info_linux.h",
@@ -113,13 +113,13 @@
     rtc_test("video_capture_tests") {
       sources = [ "test/video_capture_unittest.cc" ]
       ldflags = []
-      if (is_linux || is_mac) {
+      if (is_linux || is_chromeos || is_mac) {
         ldflags += [
           "-lpthread",
           "-lm",
         ]
       }
-      if (is_linux) {
+      if (is_linux || is_chromeos) {
         ldflags += [
           "-lrt",
           "-lXext",