Add tests for how LocalStorageContextMojo interacts with file/leveldb services.

content/test/unittests_manifest.json

Index: content/test/unittests_manifest.json
diff --git a/content/test/unittests_manifest.json b/content/test/unittests_manifest.json
new file mode 100644
index 0000000000000000000000000000000000000000..94cb81e38586c2ca65aa36ac97056b0c17a5d013
--- /dev/null
+++ b/content/test/unittests_manifest.json
@@ -0,0 +1,16 @@
+{
+  "name": "content_unittests",
+  "display_name": "Content Unittests",
+  "interface_provider_specs": {
+    "service_manager:connector": {
+      "provides": {
+        "service_manager:service_factory": [
+          "service_manager::mojom::ServiceFactory"
+         ]
+      },
+      "requires": {
+        "file": [ "file:filesystem", "file:leveldb" ]
+      }
+    }
+  }
+}