shill: serialize Manager.Services as an array of object paths

Previously, we serialized this property as an array of strings.
That was contrary to the API documentation, and caused a crash
in update_engine_client.

BUG=chromium-os:27987
TEST=unit tests, manual

Manual testing: ran on device, and checked that update_engine_client
was able to identify the technology of the default service.

Collateral change: replace PathArray with Paths (and similar
for variations, such as path_array). This makes the naming of
Paths conform to the style used for Strings, Stringmaps, etc.

Change-Id: I4ee4b9df04d3f006ab974c2092f6e515ebf5a9b8
Reviewed-on: https://gerrit.chromium.org/gerrit/18592
Commit-Ready: mukesh agrawal <quiche@chromium.org>
Reviewed-by: mukesh agrawal <quiche@chromium.org>
Tested-by: mukesh agrawal <quiche@chromium.org>
diff --git a/dbus_adaptor.h b/dbus_adaptor.h
index 1e68a8e..7385ddd 100644
--- a/dbus_adaptor.h
+++ b/dbus_adaptor.h
@@ -60,7 +60,7 @@
   static ::DBus::Variant Int32ToVariant(int32 value);
   static ::DBus::Variant KeyValueStoreToVariant(const KeyValueStore &value);
   static ::DBus::Variant PathToVariant(const ::DBus::Path &value);
-  static ::DBus::Variant PathArrayToVariant(
+  static ::DBus::Variant PathsToVariant(
       const std::vector< ::DBus::Path> &value);
   static ::DBus::Variant StringToVariant(const std::string &value);
   static ::DBus::Variant StringmapToVariant(const Stringmap &value);
@@ -75,7 +75,7 @@
   static bool IsInt16(::DBus::Signature signature);
   static bool IsInt32(::DBus::Signature signature);
   static bool IsPath(::DBus::Signature signature);
-  static bool IsPathArray(::DBus::Signature signature);
+  static bool IsPaths(::DBus::Signature signature);
   static bool IsString(::DBus::Signature signature);
   static bool IsStringmap(::DBus::Signature signature);
   static bool IsStringmaps(::DBus::Signature signature);
@@ -130,7 +130,7 @@
 
  private:
   static const char kByteArraysSig[];
-  static const char kPathArraySig[];
+  static const char kPathsSig[];
   static const char kStringmapSig[];
   static const char kStringmapsSig[];
   static const char kStringsSig[];