[Android] Generate scripts at build time to run android tests.

build/config/android/internal_rules.gni

Index: build/config/android/internal_rules.gni
diff --git a/build/config/android/internal_rules.gni b/build/config/android/internal_rules.gni
index a5a12352a2d1f7c8716cc3d5617919513f82ea8c..1f2d7236be8675c99825c18b3f0c389807ed73bd 100644
--- a/build/config/android/internal_rules.gni
+++ b/build/config/android/internal_rules.gni
@@ -1255,3 +1255,58 @@ template("generate_split_manifest") {
     ]
   }
 }
+
+# Generates a script in the output bin directory which runs the test
+# target using the test runner script in build/android/test_runner.py.
+template("test_runner_script") {
+  testonly = true
+  _test_type = invoker.test_type
+
+  action(target_name) {
+    script = "//build/android/gyp/create_test_runner_script.py"
+    depfile = "$target_gen_dir/$target_name.d"
+
+    test_runner_args = [
+      _test_type,
+      "--output-directory",
+      rebase_path(root_build_dir, root_build_dir),
+    ]
+    if (_test_type == "gtest") {
+      assert(defined(invoker.test_suite))
+      test_name = invoker.test_suite
+      test_runner_args += [
+        "--suite",
+        invoker.test_suite,
+      ]
+    } else if (_test_type == "instrumentation") {
+      assert(defined(invoker.test_apk))
+      test_name = invoker.test_apk
+      test_runner_args += [
+        "--test-apk",
+        invoker.test_apk,
+      ]
+    } else {
+      assert(false, "Invalid test type: $_test_type.")
+    }
+
+    if (defined(invoker.isolate_file)) {
+      test_runner_args += [
+        "--isolate-file-path",
+        rebase_path(invoker.isolate_file, root_build_dir),
+      ]
+    }
+
+    generated_script = "$root_build_dir/bin/run_${test_name}"
+    outputs = [
+      depfile,
+      generated_script,
+    ]
+    args = [
+      "--depfile",
+      rebase_path(depfile, root_build_dir),
+      "--script-output-path",
+      rebase_path(generated_script, root_build_dir),
+    ]
+    args += test_runner_args
+  }
+}