Allow dbus clients to silence logging when a service is unavailable.

dbus/object_proxy.h

Index: dbus/object_proxy.h
diff --git a/dbus/object_proxy.h b/dbus/object_proxy.h
index ef453054915786accb66d82268a22506b6a69240..b4ab7ae1c41ee020e46ecbed661f886379604996 100644
--- a/dbus/object_proxy.h
+++ b/dbus/object_proxy.h
@@ -14,6 +14,7 @@
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
+#include "base/string_piece.h"
 #include "base/time.h"
 
 namespace dbus {
@@ -30,11 +31,20 @@ class Signal;
 // object is is alive when callbacks referencing |this| are called.
 class ObjectProxy : public base::RefCountedThreadSafe<ObjectProxy> {
  public:
-  // Client code should use Bus::GetObjectProxy() instead of this
-  // constructor.
+  // Client code should use Bus::GetObjectProxy() or
+  // Bus::GetObjectProxyWithOptions() instead of this constructor.
   ObjectProxy(Bus* bus,
               const std::string& service_name,
-              const std::string& object_path);
+              const std::string& object_path,
+              int options);
+
+  // Options to be OR-ed together when calling Bus::GetObjectProxyWithOptions().
+  // Set the IGNORE_SERVICE_UNKNOWN_ERRORS option to silence logging of
+  // org.freedesktop.DBus.Error.ServiceUnknown errors.
+  enum Options {
+    DEFAULT_OPTIONS = 0,
+    IGNORE_SERVICE_UNKNOWN_ERRORS = 1 << 0
+  };
 
   // Special timeout constants.
   //
@@ -180,6 +190,10 @@ class ObjectProxy : public base::RefCountedThreadSafe<ObjectProxy> {
                                               DBusMessage* raw_message,
                                               void* user_data);
 
+  // Helper method for logging response errors appropriately.
+  void LogMethodCallFailure(const base::StringPiece& error_name,
+                            const base::StringPiece& error_message) const;
+
   scoped_refptr<Bus> bus_;
   std::string service_name_;
   std::string object_path_;
@@ -194,6 +208,8 @@ class ObjectProxy : public base::RefCountedThreadSafe<ObjectProxy> {
 
   std::set<std::string> match_rules_;
 
+  const bool ignore_service_unknown_errors_;
+
   DISALLOW_COPY_AND_ASSIGN(ObjectProxy);
 };