Properly define v8_enable_inspector and its override in GN.

test/BUILD.gn

 # Copyright 2016 the V8 project authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("../gni/isolate.gni")
-import("//build_overrides/v8.gni")
+import("../gni/v8.gni")
 
 group("gn_all") {
   testonly = true
 
   deps = [
     ":default_tests",
   ]
 
   if (host_os != "mac" || !is_android) {
     # These items don't compile for Android on Mac.
     deps += [
       "cctest:cctest",
       "cctest:generate-bytecode-expectations",
       "unittests:unittests",
     ]
   }
 
-  if (v8_enable_inspector_override) {
+  if (v8_enable_inspector) {
     deps += [ "inspector:inspector-test" ]
   }
 
   if (v8_test_isolation_mode != "noop") {
     deps += [
       ":benchmarks_run",
       ":bot_default_run",
       ":default_run",
       ":mozilla_run",
       ":simdjs_run",
@@ skipping 96 matching lines @@
     "..:v8_simple_regexp_fuzzer",
     "..:v8_simple_wasm_asmjs_fuzzer",
     "..:v8_simple_wasm_fuzzer",
   ]
 
   isolate = "fuzzer/fuzzer.isolate"
 }
 
 v8_isolate_run("inspector-test") {
   deps = []
-  if (v8_enable_inspector_override) {
+  if (v8_enable_inspector) {
     deps += [ "inspector:inspector-test" ]
   }
 
   isolate = "inspector/inspector.isolate"
 }
 
 v8_isolate_run("intl") {
   deps = [
     "..:d8_run",
   ]
@@ skipping 49 matching lines @@
   isolate = "unittests/unittests.isolate"
 }
 
 v8_isolate_run("webkit") {
   deps = [
     "..:d8_run",
   ]
 
   isolate = "webkit/webkit.isolate"
 }