Run findbugs on instrumentation APKs targets which include Java source files

build/config/android/rules.gni

 # Copyright 2014 The Chromium 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("//base/android/linker/config.gni")
 import("//build/config/android/config.gni")
 import("//build/config/android/internal_rules.gni")
 import("//build/toolchain/toolchain.gni")
 import("//third_party/android_platform/config.gni")
 import("//tools/grit/grit_rule.gni")
@@ skipping 1867 matching lines @@
   android_apk(_apk_target_name) {
     deps = []
     data_deps = []
     forward_variables_from(invoker, "*")
     deps += [ "//testing/android/broker:broker_java" ]
     data_deps += [
       "//testing/android/driver:driver_apk",
       "//tools/android/forwarder2",
       "//tools/android/md5sum",
     ]
-    run_findbugs = false
+
+    run_findbugs =
+        defined(invoker.run_findbugs) && invoker.run_findbugs &&
+        (defined(invoker.java_files) || defined(invoker.DEPRECATED_java_in_dir))
   }
 
   group(target_name) {
     public_deps = [
       ":$_apk_target_name",
       ":$_test_runner_target_name",
     ]
   }
 }
 
@@ skipping 303 matching lines @@
   }
 
   android_library(target_name) {
     java_files = []
     srcjar_deps = [ ":${_template_name}__protoc_java" ]
     deps = [
       "//third_party/android_protobuf:protobuf_nano_javalib",
     ]
   }
 }