Changing SpawnChild to return a struct.

testing/android/native_test/BUILD.gn

Index: testing/android/native_test/BUILD.gn
diff --git a/testing/android/native_test/BUILD.gn b/testing/android/native_test/BUILD.gn
index 728cec028b93ae4ef2cfe0c6c5754aa61be1d1c8..fbcc5628bad405ae562154f8c7226b7d1ad964c8 100644
--- a/testing/android/native_test/BUILD.gn
+++ b/testing/android/native_test/BUILD.gn
@@ -40,6 +40,7 @@ android_library("native_main_runner_java") {
   java_files = [ "java/src/org/chromium/native_test/MainRunner.java" ]
   deps = [
     "//base:base_java",
+    "//mojo/public/java:system_java",
   ]
 }
 
@@ -68,4 +69,7 @@ generate_jni("native_test_jni_headers") {
     "java/src/org/chromium/native_test/NativeTest.java",
   ]
   jni_package = "testing"
+  deps = [
+    "//mojo/public/java:system_java",
+  ]
 }