D-Bus: allow multiple signal handlers for a signal

dbus/object_proxy.h

Index: dbus/object_proxy.h
diff --git a/dbus/object_proxy.h b/dbus/object_proxy.h
index 23c0f4ce76055f225225bb44032a1b635554ef38..44652d63d218e75109b49dad1b3841e90fc3ec1e 100644
--- a/dbus/object_proxy.h
+++ b/dbus/object_proxy.h
@@ -10,6 +10,7 @@
 #include <map>
 #include <set>
 #include <string>
+#include <vector>
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
@@ -222,7 +223,7 @@ class CHROME_DBUS_EXPORT ObjectProxy
 
   // Runs the method. Helper function for HandleMessage().
   void RunMethod(base::TimeTicks start_time,
-                 SignalCallback signal_callback,
+                 std::vector<SignalCallback> signal_callbacks,
                  Signal* signal);
 
   // Redirects the function call to HandleMessage().
@@ -268,8 +269,8 @@ class CHROME_DBUS_EXPORT ObjectProxy
   bool filter_added_;
 
   // The method table where keys are absolute signal names (i.e. interface
-  // name + signal name), and values are the corresponding callbacks.
-  typedef std::map<std::string, SignalCallback> MethodTable;
+  // name + signal name), and values are lists of the corresponding callbacks.
+  typedef std::map<std::string, std::vector<SignalCallback> > MethodTable;
   MethodTable method_table_;
 
   // The callback called when NameOwnerChanged signal is received.