Implement Android key/value backup

chrome/test/BUILD.gn

Index: chrome/test/BUILD.gn
diff --git a/chrome/test/BUILD.gn b/chrome/test/BUILD.gn
index ed666848317475ac61ebff065058c7841df78a35..54d4bed53d7d4313ddc033c9db760699f63b18b5 100644
--- a/chrome/test/BUILD.gn
+++ b/chrome/test/BUILD.gn
@@ -3019,6 +3019,7 @@ test("unit_tests") {
     "../browser/android/history_report/usage_reports_buffer_backend_unittest.cc",
 
     # TODO(newt): move this to test_support_unit?
+    "../browser/android/chrome_backup_agent_unittest.cc",
     "../browser/android/mock_location_settings.cc",
     "../browser/android/mock_location_settings.h",
     "../browser/android/net/external_estimate_provider_android_unittest.cc",
@@ -3498,6 +3499,7 @@ test("unit_tests") {
     sources -= [ "../browser/policy/policy_path_parser_unittest.cc" ]
     deps += [
       ":unit_tests_java",
+      "//chrome/browser:jni_headers",
       "//components/gcm_driver/instance_id/android:instance_id_driver_java",
       "//components/gcm_driver/instance_id/android:instance_id_driver_test_support_java",
       "//components/offline_pages:test_support",