Fix some gn check issues in //sandbox

Bug: 1097376, 949535
Change-Id: I50caa1db4ff41bb8de5ebc98eb137ec80d410faa
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2302811
Commit-Queue: Nico Weber <thakis@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#789468}

.gn

@@ -212,9 +212,7 @@ no_check_targets = [
   "//remoting:*",  # 27 errors
   "//sandbox/linux:*",  # 13 errors
   "//sandbox/mac:*",  # 14 errors
-  "//sandbox/policy:*",  # 1 error
   "//sandbox/win:*",  # 7 errors
-  "//sandbox:*",  # 3 errors
 
   # //third_party/blink/*, https://crbug.com/800764
   "//third_party/blink/common:*",  # 9 errors

sandbox/BUILD.gn

@@ -56,7 +56,10 @@ fuzzer_test("sandbox_ipc_fuzzer") {
   if (!is_win) {
     defines = [ "SANDBOX_FUZZ_TARGET" ]
   }
-  deps = [ "//base" ]
+  deps = [
+    ":sandbox",
+    "//base",
+  ]
   dict = "ipc.dict"
   libfuzzer_options = [ "max_len=1024" ]
 }

sandbox/policy/BUILD.gn

@@ -154,6 +154,7 @@ source_set("tests") {
   deps = [
     ":policy",
     "//base",
+    "//base/test:test_support",
     "//testing/gtest",
   ]