debugd: Add TestICMP functionality.

chromeos/dbus/debug_daemon_client.h

Index: chromeos/dbus/debug_daemon_client.h
diff --git a/chromeos/dbus/debug_daemon_client.h b/chromeos/dbus/debug_daemon_client.h
index 07e52ba0b7b3ba6b031f1034da7c759dc34b90ec..91b9ae017d90c202e1fdfb4ff63c9d454a87839c 100644
--- a/chromeos/dbus/debug_daemon_client.h
+++ b/chromeos/dbus/debug_daemon_client.h
@@ -96,6 +96,20 @@ class CHROMEOS_EXPORT DebugDaemonClient {
   // Returns an empty SystemTracingCallback that does nothing.
   static StopSystemTracingCallback EmptyStopSystemTracingCallback();
 
+  // Called once TestICMP() is complete. Takes two parameters:
+  // - succeeded: information was obtained successfully.
+  // - status: information about ICMP connectivity to a specified host as json.
+  //   For details please refer to
+  //   https://gerrit.chromium.org/gerrit/#/c/30310/2/src/helpers/icmp.cc
+  typedef base::Callback<void(bool succeeded, const std::string& status)>
+      TestICMPCallback;
+
+  // Tests ICMP connectivity to a specified host. The |host| contains an IPv4
+  // or IPv6 address.

[satorux1, 2012/08/17 21:13:16]

could you add some examples? can this be a host name like www.google.com?

[hshi1, 2012/08/17 21:23:00]

No this must be numeric IP address. Done.

+  virtual void TestICMP(
+      const std::string& host,

[satorux1, 2012/08/17 21:13:16]

if this only accepts IP address, host -> ip_address

nit: move this to the previous line? 

[hshi1, 2012/08/17 21:23:00]

Done.

+      const TestICMPCallback& callback) = 0;
+
   // Factory function, creates a new instance and returns ownership.
   // For normal usage, access the singleton via DBusThreadManager::Get().
   static DebugDaemonClient* Create(DBusClientImplementationType type,