[libFuzzer][Windows] Fix for ToT Clang bot

Don't allow building of afl_driver since it isn't intended to be built
on Windows.

Change-Id: I8aeb89b5cf98f1998258847b60a8e12a465d3ca9
Bug: 903078
Reviewed-on: https://chromium-review.googlesource.com/c/1342772
Commit-Queue: Hans Wennborg <hans@chromium.org>
Reviewed-by: Hans Wennborg <hans@chromium.org>
Reviewed-by: Max Moroz <mmoroz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#609949}

BUILD.gn

@@ -724,11 +724,17 @@ group("gn_all") {
       (is_win && (use_drfuzz || use_libfuzzer)) || (use_libfuzzer && is_mac)) {
     deps += [
       "//testing/libfuzzer/fuzzers",
-      "//testing/libfuzzer/tests:libfuzzer_tests",
       "//third_party/icu/fuzzers",
       "//third_party/qcms:fuzzers",
       "//third_party/zlib/contrib/tests/fuzzers",
     ]
+
+    # TODO(crbug.com/906751): Get the libFuzzer tests working on Windows.
+    # Disable them for now becaue they cause the Windows clang ToT builder to
+    # fail.
+    if (!is_win) {
+      deps += [ "//testing/libfuzzer/tests:libfuzzer_tests" ]
+    }
   }
 
   if (enable_nacl) {

testing/libfuzzer/tests/BUILD.gn

@@ -7,7 +7,10 @@
 import("//testing/test.gni")
 import("//testing/libfuzzer/fuzzer_test.gni")
 
-test("libfuzzer_tests") {
+# TODO(crbug.com/906751): Get the tests working on Windows. Disable them for now
+# becaue they cause the Windows clang ToT builder to fail.
+if (!is_win) {
+  test("libfuzzer_tests") {
     sources = [
       "fuzzer_launcher_test.cc",
     ]
@@ -27,6 +30,7 @@ test("libfuzzer_tests") {
       ":check_fuzzer_config",
       ":check_seed_corpus_archive",
     ]
+  }
 }
 
 fuzzer_test("test_dict_only") {

third_party/libFuzzer/BUILD.gn

@@ -50,11 +50,13 @@ source_set("libfuzzer") {
   configs += fuzzing_engine_add_configs
 }
 
-source_set("afl_driver") {
+if (use_afl) {
+  source_set("afl_driver") {
     sources = [
       "src/afl/afl_driver.cpp",
     ]
 
     configs -= fuzzing_engine_remove_configs
     configs += fuzzing_engine_add_configs
+  }
 }