Move chromeos::GetInterfacesFromIntrospectResult into IntrospectableClient

chromeos/dbus/introspectable_client.cc

Index: chromeos/dbus/introspectable_client.cc
diff --git a/chromeos/dbus/introspectable_client.cc b/chromeos/dbus/introspectable_client.cc
index d29563f37acf6dbfa2311efa6b4b67c1498d4a78..5f666841a3623690ca65b937bd135a18db0473a5 100644
--- a/chromeos/dbus/introspectable_client.cc
+++ b/chromeos/dbus/introspectable_client.cc
@@ -13,6 +13,7 @@
 #include "dbus/message.h"
 #include "dbus/object_path.h"
 #include "dbus/object_proxy.h"
+#include "third_party/libxml/chromium/libxml_utils.h"
 
 namespace {
 
@@ -20,6 +21,10 @@ namespace {
 const char kIntrospectableInterface[] = "org.freedesktop.DBus.Introspectable";
 const char kIntrospect[] = "Introspect";
 
+// String constants used for parsing D-Bus Introspection XML data.
+const char kInterfaceNode[] = "interface";
+const char kInterfaceNameAttribute[] = "name";
+
 }  // namespace
 
 namespace chromeos {
@@ -105,6 +110,39 @@ IntrospectableClient::~IntrospectableClient() {
 }
 
 // static
+std::vector<std::string>
+IntrospectableClient::GetInterfacesFromIntrospectResult(
+    const std::string& xml_data) {
+  std::vector<std::string> interfaces;
+
+  XmlReader reader;
+  if (!reader.Load(xml_data))
+    return interfaces;
+
+  do {
+    // Skip to the next open tag, exit when done.
+    while (!reader.SkipToElement()) {
+      if (!reader.Read()) {
+        return interfaces;
+      }
+    }
+
+    // Only look at interface nodes.
+    if (reader.NodeName() != kInterfaceNode)
+      continue;
+
+    // Skip if missing the interface name.
+    std::string interface_name;
+    if (!reader.NodeAttribute(kInterfaceNameAttribute, &interface_name))
+      continue;
+
+    interfaces.push_back(interface_name);
+  } while (reader.Read());
+
+  return interfaces;
+}
+
+// static
 IntrospectableClient* IntrospectableClient::Create(
     DBusClientImplementationType type,
     dbus::Bus* bus) {