Add path open errors from the permission broker to the device log.

chromeos/dbus/permission_broker_client.cc

Index: chromeos/dbus/permission_broker_client.cc
diff --git a/chromeos/dbus/permission_broker_client.cc b/chromeos/dbus/permission_broker_client.cc
index fb0c934db1c7175d8c69c0b3675d540bf058c7ff..1ec95714d607cacd0d7d4c53c5b12e09bd541125 100644
--- a/chromeos/dbus/permission_broker_client.cc
+++ b/chromeos/dbus/permission_broker_client.cc
@@ -42,14 +42,17 @@ class PermissionBrokerClientImpl : public PermissionBrokerClient {
   }
 
   void OpenPath(const std::string& path,
-                const OpenPathCallback& callback) override {
+                const OpenPathCallback& callback,
+                const ErrorCallback& error_callback) override {
     dbus::MethodCall method_call(kPermissionBrokerInterface, kOpenPath);
     dbus::MessageWriter writer(&method_call);
     writer.AppendString(path);
-    proxy_->CallMethod(
+    proxy_->CallMethodWithErrorCallback(
         &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
         base::Bind(&PermissionBrokerClientImpl::OnOpenPathResponse,
-                   weak_ptr_factory_.GetWeakPtr(), callback));
+                   weak_ptr_factory_.GetWeakPtr(), callback),
+        base::Bind(&PermissionBrokerClientImpl::OnError,
+                   weak_ptr_factory_.GetWeakPtr(), error_callback));
   }
 
   void RequestTcpPortAccess(uint16_t port,
@@ -133,15 +136,23 @@ class PermissionBrokerClientImpl : public PermissionBrokerClient {
   void OnOpenPathResponse(const OpenPathCallback& callback,
                           dbus::Response* response) {
     dbus::FileDescriptor fd;
+    dbus::MessageReader reader(response);
+    if (!reader.PopFileDescriptor(&fd))
+      LOG(WARNING) << "Could not parse response: " << response->ToString();
+    callback.Run(std::move(fd));
+  }
+
+  void OnError(const ErrorCallback& callback, dbus::ErrorResponse* response) {
+    std::string error_name;
+    std::string error_message;
     if (response) {
       dbus::MessageReader reader(response);
-      if (!reader.PopFileDescriptor(&fd))
-        LOG(WARNING) << "Could not parse response: " << response->ToString();
+      error_name = response->GetErrorName();
+      reader.PopString(&error_message);
     } else {
-      LOG(WARNING) << "Access request method call failed.";
+      error_name = "org.chromium.Error.NoResponse";

[stevenjb, 2016/02/10 00:01:02]

nit: define at the top of the file:

const char kNoResponseError[] = "org.chromium.Error.NoResponse"; 

[Reilly Grant (use Gerrit), 2016/02/10 00:16:32]

Done.

     }
-
-    callback.Run(std::move(fd));
+    callback.Run(error_name, error_message);
   }
 
   dbus::ObjectProxy* proxy_;