cobalt: Reenable cobalt_unitests on non-Android (e.g. Linux) (#4925)

These tests were disabled because they failed to compile on  
e.g. Linux (b/375243230). But we need them enabled otherwise  
we cannot add more Cobalt unittests, e.g. in #4916.

This CL reenables those and leaves NOTIMPLEMENTED()s+TODO()s  
where appropriate.

Bug: b/374213479

base/system/sys_info_starboard.cc

@@ -18,6 +18,9 @@
 
 #if BUILDFLAG(IS_ANDROID)
 #include <sys/system_properties.h>
+#else
+// TODO(b/374213479): Remove after the functions below are implemented.
+#include "base/notreached.h"
 #endif  // BUILDFLAG(IS_ANDROID)
 
 namespace base {
@@ -61,7 +64,31 @@ std::string SbSysInfo::Brand() {
   __system_property_get("ro.product.brand", brand_str);
   return std::string(brand_str);
 }
+#else
+std::string SbSysInfo::OriginalDesignManufacturer() {
+  // TODO(b/374213479): Implement for non-Android.
+  NOTIMPLEMENTED();
+  return "";
+}
+
+std::string SbSysInfo::ChipsetModelNumber() {
+  // TODO(b/374213479): Implement for non-Android.
+  NOTIMPLEMENTED();
+  return "";
+}
+
+std::string SbSysInfo::ModelYear() {
+  // TODO(b/374213479): Implement for non-Android.
+  NOTIMPLEMENTED();
+  return "";
+}
+
+std::string SbSysInfo::Brand() {
+  // TODO(b/374213479): Implement for non-Android.
+  NOTIMPLEMENTED();
+  return "";
+}
 #endif  // BUILDFLAG(IS_ANDROID)
 
 }  // namespace starboard
-}  // namespace base
+}  // namespace base

cobalt/BUILD.gn

@@ -81,18 +81,16 @@ action("cobalt_build_info") {
   ]
 }
 
-if (is_android) {
-  test("cobalt_unittests") {
-    testonly = true
+test("cobalt_unittests") {
+  testonly = true
 
-    sources = [ "//cobalt/user_agent/user_agent_platform_info_test.cc" ]
+  sources = [ "//cobalt/user_agent/user_agent_platform_info_test.cc" ]
 
-    deps = [
-      "//base/test:run_all_unittests",
-      "//cobalt/user_agent",
-      "//starboard:starboard_group",
-      "//testing/gmock",
-      "//testing/gtest",
-    ]
-  }
+  deps = [
+    "//base/test:run_all_unittests",
+    "//cobalt/user_agent",
+    "//starboard:starboard_group",
+    "//testing/gmock",
+    "//testing/gtest",
+  ]
 }

cobalt/build/testing/targets/linux-x64x11/test_targets.json

@@ -4,6 +4,7 @@
     "base:base_unittests",
     "cc:cc_perftests",
     "cc:cc_unittests",
+    "cobalt:cobalt_unittests",
     "components/viz:viz_perftests",
     "components/viz:viz_unittests",
     "crypto:crypto_unittests",
@@ -36,6 +37,7 @@
     "out/linux-x64x11_devel/base_unittests",
     "out/linux-x64x11_devel/cc_perftests",
     "out/linux-x64x11_devel/cc_unittests",
+    "out/linux-x64x11_devel/cobalt_unittests",
     "out/linux-x64x11_devel/viz_perftests",
     "out/linux-x64x11_devel/viz_unittests",
     "out/linux-x64x11_devel/crypto_unittests",