Expand is_linux to is_linux || is_chromeos.

Currnetly ,is_linux GN variable is set to true on Chrome OS build,
but it is planned to be set false. This CL is the preparation
to keep the bahavior compatible.

Bug: chromium:1110266
Test: Build locally.
Change-Id: Iffbfafe3ac5b00899804afa7471a04709046610a
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/28340
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
Commit-Queue: Hidehiko Abe <hidehiko@chromium.org>
diff --git a/scripts/dawn_features.gni b/scripts/dawn_features.gni
index 9d3cbfc..6f4f01e 100644
--- a/scripts/dawn_features.gni
+++ b/scripts/dawn_features.gni
@@ -52,8 +52,8 @@
   dawn_enable_opengl = is_linux && !is_chromeos
 
   # Enables the compilation of Dawn's Vulkan backend
-  dawn_enable_vulkan =
-      is_linux || is_win || is_fuchsia || is_android || dawn_use_swiftshader
+  dawn_enable_vulkan = is_linux || is_chromeos || is_win || is_fuchsia ||
+                       is_android || dawn_use_swiftshader
 
   # Enable use of reflection compiler in spirv-cross. This is needed
   # if performing reflection on systems that the platform language