Skip absl_hardening_tests when building Abseil standalone

Previously, absl_hardening_tests was updated to only not depend on
//base/test:run_all_unittests when building Abseil as part of a
standalone build (!build_with_chromium). However, while this fixed the
gn dependency errors in ANGLE, building all of ANGLE (not just the
"angle" target) still failed due to missing main(), which is built as
part of //base/test:run_all_unittests.

Instead, the entirety of absl_hardening_tests will be excluded when
building outside of Chromium, which allows the ANGLE build to complete
successfully.

Bug: angleproject:4873
Test: ~/code/chromium/src/third_party/angle$ ninja -v -C out/ClangDebug
Change-Id: Idc2d81d03a454f7aa280a2b05f332c231904408d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2350195Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Mirko Bonadei <mbonadei@chromium.org>
Commit-Queue: Mirko Bonadei <mbonadei@chromium.org>
Cr-Commit-Position: refs/heads/master@{#797164}

third_party/abseil-cpp/BUILD.gn

@@ -191,20 +191,21 @@ if (!is_component_build) {
   }
 }
 
-test("absl_hardening_tests") {
-  testonly = true
-  sources = [ "absl_hardening_test.cc" ]
-  deps = [
-    "//third_party/abseil-cpp/absl/base:config",
-    "//third_party/abseil-cpp/absl/container:fixed_array",
-    "//third_party/abseil-cpp/absl/container:inlined_vector",
-    "//third_party/abseil-cpp/absl/strings",
-    "//third_party/abseil-cpp/absl/types:optional",
-    "//third_party/abseil-cpp/absl/types:span",
-    "//third_party/abseil-cpp/absl/types:variant",
-    "//third_party/googletest:gtest",
-  ]
-  if (build_with_chromium) {
-    deps += [ "//base/test:run_all_unittests" ]
+if (build_with_chromium) {
+  test("absl_hardening_tests") {
+    testonly = true
+    sources = [ "absl_hardening_test.cc" ]
+    deps = [
+      "//base/test:run_all_unittests",
+      "//third_party/abseil-cpp/absl/base:config",
+      "//third_party/abseil-cpp/absl/container:fixed_array",
+      "//third_party/abseil-cpp/absl/container:inlined_vector",
+      "//third_party/abseil-cpp/absl/strings",
+      "//third_party/abseil-cpp/absl/types:optional",
+      "//third_party/abseil-cpp/absl/types:span",
+      "//third_party/abseil-cpp/absl/types:variant",
+      "//third_party/googletest:gtest",
+    ]
   }
 }
+