Add --test-jar arg to test_runner to explicitly specify its path.

build/config/android/internal_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.
 
 # Do not add any imports to non-//build directories here.
 # Some projects (e.g. V8) do not have non-build directories DEPS'ed in.
 import("//build_overrides/build.gni")
 import("//build/config/android/config.gni")
 import("//build/config/dcheck_always_on.gni")
 import("//build/config/sanitizers/sanitizers.gni")
@@ skipping 496 matching lines @@
       assert(defined(invoker.test_suite))
       test_runner_args += [
         "--suite",
         invoker.test_suite,
       ]
     } else if (_test_type == "instrumentation") {
       _test_apk = "@FileArg($_rebased_apk_build_config:deps_info:apk_path)"
       if (_incremental_install) {
         _test_apk = "@FileArg($_rebased_apk_build_config:deps_info:incremental_apk_path)"
       }
-      test_runner_args += [ "--test-apk=$_test_apk" ]
+      test_runner_args += [
+        "--test-apk=$_test_apk",
+        "--test-jar",
+        rebase_path(invoker.test_jar, root_build_dir),
+      ]
       if (defined(invoker.apk_under_test)) {
         deps += [ "${invoker.apk_under_test}__build_config" ]
         _apk_under_test_build_config =
             get_label_info(invoker.apk_under_test, "target_gen_dir") + "/" +
             get_label_info(invoker.apk_under_test, "name") + ".build_config"
         _rebased_apk_under_test_build_config =
             rebase_path(_apk_under_test_build_config, root_build_dir)
         _apk_under_test =
             "@FileArg($_rebased_apk_under_test_build_config:deps_info:apk_path)"
         if (_incremental_install) {
@@ skipping 2202 matching lines @@
         rebase_path(root_build_dir, root_build_dir),
         "--packed-libraries-dir",
         rebase_path(_packed_libraries_dir, root_build_dir),
         "--libraries=${invoker.libraries_filearg}",
         "--filelistjson",
         rebase_path(invoker.file_list_json, root_build_dir),
       ]
     }
   }
 }