Revert of [gn] Add unittests

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index f432d288f32de1e02ef2bef6a9d446e7f2be043b..6b2408e3f15da55234a5a33608a3b7dde7e9f32e 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -2021,33 +2021,6 @@
 # Public targets
 #
 
-want_v8_shell = (
-    (current_toolchain == host_toolchain && v8_toolset_for_shell == "host") ||
-    (current_toolchain == v8_snapshot_toolchain &&
-     v8_toolset_for_shell == "host") ||
-    (current_toolchain != host_toolchain && v8_toolset_for_shell == "target"))
-
-group("gn_all") {
-  testonly = true
-
-  deps = [
-    ":d8",
-  ]
-
-  if (want_v8_shell) {
-    deps += [
-      ":v8_shell",
-    ]
-  }
-
-  if (host_os != "mac" || !is_android) {
-    # These items don't compile for Android on Mac.
-    deps += [
-      "test/unittests:unittests",
-    ]
-  }
-}
-
 if (is_component_build) {
   component("v8") {
     sources = [
@@ -2120,7 +2093,10 @@
   }
 }
 
-if (want_v8_shell) {
+if ((current_toolchain == host_toolchain && v8_toolset_for_shell == "host") ||
+    (current_toolchain == v8_snapshot_toolchain &&
+     v8_toolset_for_shell == "host") ||
+    (current_toolchain != host_toolchain && v8_toolset_for_shell == "target")) {
   executable("v8_shell") {
     sources = [
       "samples/shell.cc",