[Cast Convergence] Replace is_chromecast with new args

Replace `is_chromecast` with `is_castos` and `is_cast_android` as
appropriate. See linked bug for further context.

Bug: chromium:1219802
Change-Id: If24af59e058940b7259cf4f1d9a3ba2ee0449cdb
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/265601
Reviewed-by: Henrik Andreassson <henrika@webrtc.org>
Reviewed-by: David Dorwin <ddorwin@google.com>
Reviewed-by: Mark Foltz <mfoltz@chromium.org>
Commit-Queue: Ryan Keane <rwkeane@google.com>
Cr-Commit-Position: refs/heads/main@{#37230}
diff --git a/modules/desktop_capture/BUILD.gn b/modules/desktop_capture/BUILD.gn
index 64ce1a2..0c59ecd 100644
--- a/modules/desktop_capture/BUILD.gn
+++ b/modules/desktop_capture/BUILD.gn
@@ -287,7 +287,7 @@
       # Chromecast build config overrides `WEBRTC_USE_PIPEWIRE` even when
       # `rtc_use_pipewire` is not set, which causes pipewire_config to not be
       # included in targets. More details in: webrtc:13898
-      if (is_linux && !is_chromecast) {
+      if (is_linux && !is_castos) {
         defines += [ "WEBRTC_USE_GIO" ]
       }
     }
@@ -396,7 +396,7 @@
     "window_finder.cc",
     "window_finder.h",
   ]
-  if (is_linux && !is_chromecast && rtc_use_pipewire) {
+  if (is_linux && !is_castos && rtc_use_pipewire) {
     sources += [ "desktop_capture_metadata.h" ]
   }
   if (is_mac) {
diff --git a/webrtc.gni b/webrtc.gni
index 264f0d6..c91c25b 100644
--- a/webrtc.gni
+++ b/webrtc.gni
@@ -65,7 +65,7 @@
     # When WebRTC is built as part of Chromium it should exclude the default
     # implementation of field_trial unless it is building for NACL or
     # Chromecast.
-    rtc_exclude_field_trial_default = !is_nacl && !is_chromecast
+    rtc_exclude_field_trial_default = !is_nacl && !is_castos && !is_cast_android
   } else {
     rtc_exclude_field_trial_default = false
   }