[LPM] Make psuedo-protobuf_full a static_library like the real one.

Change-Id: I5553b7df35bbed19fe8c99645db5265aee67d776
Reviewed-on: https://chromium-review.googlesource.com/1147609
Commit-Queue: Jonathan Metzman <metzman@chromium.org>
Reviewed-by: Martin Barbella <mbarbella@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577354}

third_party/libprotobuf-mutator/BUILD.gn

@@ -98,13 +98,14 @@ fuzzable_proto_library("override_lite_runtime_plugin_test_fuzzer_proto") {
   ]
 }
 
-# Component that can provide protobuf_full to non-testonly targets
-component("protobuf_full") {
-  # Stop people from using me by accident.
-  if (!use_libfuzzer) {
-    testonly = true
-  }
+# Avoid CQ complaints on platforms we don't care about (ie: iOS).
+# Also prevent people from using this to include protobuf_full into a production
+# build of Chrome.
+if (use_libfuzzer) {
+  # Component that can provide protobuf_full to non-testonly targets
+  static_library("protobuf_full") {
     public_deps = [
       "//third_party/protobuf:protobuf_full",
     ]
+  }
 }