Revert of chromeos, GN: make it possible to build many unittests.

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index 521f13fc12a8e72cceb4de7d2a53f8c5105d853a..3fd7ff08c948891953a2eb32c0f241d0a21f3cdb 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -424,7 +424,7 @@
     ]
   }
 
-  if (is_android || is_win || is_linux) {
+  if (is_android || is_win || (is_linux && !is_chromeos)) {
     deps += [
       "//base:build_utf8_validator_tables",
       "//base:check_example",
@@ -458,6 +458,8 @@
         "//courgette:courgette_fuzz",
         "//courgette:courgette_minimal_tool",
         "//courgette:courgette_unittests",
+        "//media/cast:generate_barcode_video",
+        "//media/cast:generate_timecode_audio",
         "//net:crash_cache",
         "//net:crl_set_dump",
         "//net:dns_fuzz_stub",
@@ -473,12 +475,6 @@
         "//third_party/leveldatabase:env_chromium_unittests",
         "//third_party/libaddressinput:libaddressinput_unittests",
       ]
-      if (!is_chromeos) {
-        deps += [
-          "//media/cast:generate_barcode_video",
-          "//media/cast:generate_timecode_audio",
-        ]
-      }
     }
     if (!is_android && !is_linux) {
       # TODO(dpranke): Re-enable this once
@@ -655,7 +651,7 @@
     ]
   }
 
-  if (is_linux && !is_chromecast) {
+  if (is_linux && !is_chromeos && !is_chromecast) {
     # TODO(GYP): Figure out if any of these should be in gn_all
     # and figure out how cross-platform they are
     deps += [
@@ -671,6 +667,7 @@
       "//components/rappor:unit_tests",
       "//components/sessions:unit_tests",
       "//media/blink:media_blink_unittests",
+      "//media/cast:udp_proxy",
       "//native_client/src/trusted/debug_stub:gdb_rsp_unittest",
       "//storage/browser:dump_file_system",
       "//third_party/angle:libANGLE",
@@ -722,9 +719,6 @@
       "//ui/views/examples:views_examples_exe",
     ]
 
-    if (!is_chromeos) {
-      deps += [ "//media/cast:udp_proxy" ]
-    }
     if (target_cpu == "x86" || target_cpu == "x64") {
       if (!is_android) {
         deps += [ "//chrome/test:load_library_perf_tests" ]