Change ITestClient to be similar to IChildProcessService.

base/test/BUILD.gn

Index: base/test/BUILD.gn
diff --git a/base/test/BUILD.gn b/base/test/BUILD.gn
index 057e3071737296cffb9a29598ac87ba5ba9a5639..d79d7f32c8e391cd5df185c8b97f25e8a3e35f77 100644
--- a/base/test/BUILD.gn
+++ b/base/test/BUILD.gn
@@ -356,6 +356,7 @@ if (is_android) {
     ]
     srcjar_deps = [ ":test_support_java_aidl" ]
     java_files = [
+      "android/java/src/org/chromium/base/ChildProcessConstants.java",
       "android/java/src/org/chromium/base/MainReturnCodeResult.java",
       "android/java/src/org/chromium/base/MultiprocessTestClientLauncher.java",
       "android/java/src/org/chromium/base/MultiprocessTestClientService.java",
@@ -374,7 +375,9 @@ if (is_android) {
       "//base/android/java/src",
     ]
     sources = [
+      "android/java/src/org/chromium/base/ITestCallback.aidl",
       "android/java/src/org/chromium/base/ITestClient.aidl",
+      "android/java/src/org/chromium/base/ITestController.aidl",
     ]
   }
 }