3 files changed, 46 insertions, 29 deletions

diff --git a/chrome/browser/service/service_process_control.cc b/chrome/browser/service/service_process_control.cc
index ccce948..2873ddc 100644
--- a/chrome/browser/service/service_process_control.cc
+++ b/chrome/browser/service/service_process_control.cc
@@ -96,8 +96,7 @@ class ServiceProcessControl::Launcher
 
 // ServiceProcessControl implementation.
 ServiceProcessControl::ServiceProcessControl(Profile* profile)
-    : profile_(profile),
-      message_handler_(NULL) {
+    : profile_(profile) {
 }
 
 ServiceProcessControl::~ServiceProcessControl() {
@@ -279,10 +278,11 @@ void ServiceProcessControl::Observe(NotificationType type,
 }
 
 void ServiceProcessControl::OnGoodDay() {
-  if (!message_handler_)
-    return;
-
-  message_handler_->OnGoodDay();
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  for (std::set<MessageHandler*>::iterator it = message_handlers_.begin();
+       it != message_handlers_.end(); ++it) {
+    (*it)->OnGoodDay();
+  }
 }
 
 void ServiceProcessControl::OnCloudPrintProxyIsEnabled(bool enabled,
@@ -297,9 +297,9 @@ void ServiceProcessControl::OnCloudPrintProxyIsEnabled(bool enabled,
 void ServiceProcessControl::OnRemotingHostInfo(
     remoting::ChromotingHostInfo host_info) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  if (remoting_host_status_callback_ != NULL) {
-    remoting_host_status_callback_->Run(host_info);
-    remoting_host_status_callback_.reset();
+  for (std::set<MessageHandler*>::iterator it = message_handlers_.begin();
+       it != message_handlers_.end(); ++it) {
+    (*it)->OnRemotingHostInfo(host_info);
   }
 }
 
@@ -335,11 +335,18 @@ bool ServiceProcessControl::DisableRemotingHost() {
   return Send(new ServiceMsg_DisableRemotingHost());
 }
 
-bool ServiceProcessControl::GetRemotingHostStatus(
-    GetRemotingHostStatusCallback* status_callback) {
-  DCHECK(status_callback);
-  remoting_host_status_callback_.reset(status_callback);
+bool ServiceProcessControl::RequestRemotingHostStatus() {
   return Send(new ServiceMsg_GetRemotingHostInfo);
 }
 
+void ServiceProcessControl::AddMessageHandler(
+    MessageHandler* message_handler) {
+  message_handlers_.insert(message_handler);
+}
+
+void ServiceProcessControl::RemoveMessageHandler(
+    MessageHandler* message_handler) {
+  message_handlers_.erase(message_handler);
+}
+
 DISABLE_RUNNABLE_METHOD_REFCOUNT(ServiceProcessControl);
diff --git a/chrome/browser/service/service_process_control.h b/chrome/browser/service/service_process_control.h
index 9162736..78c3141 100644
--- a/chrome/browser/service/service_process_control.h
+++ b/chrome/browser/service/service_process_control.h
@@ -6,6 +6,7 @@
 #define CHROME_BROWSER_SERVICE_SERVICE_PROCESS_CONTROL_H_
 
 #include <queue>
+#include <set>
 #include <string>
 #include <vector>
 
@@ -41,15 +42,20 @@ class ServiceProcessControl : public IPC::Channel::Sender,
   typedef IDMap<ServiceProcessControl>::iterator iterator;
   typedef std::queue<IPC::Message> MessageQueue;
   typedef Callback1<const remoting::ChromotingHostInfo&>::Type
-      GetRemotingHostStatusCallback;
+      RemotingHostStatusHandler;
 
   // An interface for handling messages received from the service process.
   class MessageHandler {
    public:
     virtual ~MessageHandler() {}
+
     // This is a test signal sent from the service process. This can be used
     // the healthiness of the service.
     virtual void OnGoodDay() = 0;
+
+    // Called when we receive reply to remoting host status request.
+    virtual void OnRemotingHostInfo(
+        const remoting::ChromotingHostInfo& host_info) = 0;
   };
 
   // Construct a ServiceProcessControl with |profile|..
@@ -103,29 +109,30 @@ class ServiceProcessControl : public IPC::Channel::Sender,
   // Return true if the message was sent.
   bool Shutdown();
 
-  // Send a message to the service process to request a response
-  // containing the enablement status of the cloud print proxy and the
-  // registered email address.  The callback gets the information when
-  // received.
+  // Send request for cloud print proxy status and the registered
+  // email address. The callback gets the information when received.
   bool GetCloudPrintProxyStatus(
       Callback2<bool, std::string>::Type* cloud_print_status_callback);
 
   // Send a message to enable the remoting service in the service process.
   // Return true if the message was sent.
   bool SetRemotingHostCredentials(const std::string& user,
-                                    const std::string& auth_token);
+                                  const std::string& auth_token);
 
   bool EnableRemotingHost();
   bool DisableRemotingHost();
 
-  bool GetRemotingHostStatus(
-      GetRemotingHostStatusCallback* status_callback);
+  // Send request for current status of the remoting service.
+  bool RequestRemotingHostStatus();
+
+  // Add a message handler for receiving messages from the service
+  // process.
+  void AddMessageHandler(MessageHandler* message_handler);
 
-  // Set the message handler for receiving messages from the service process.
-  // TODO(hclam): Allow more than 1 handler.
-  void SetMessageHandler(MessageHandler* message_handler) {
-    message_handler_ = message_handler;
-  }
+  // Remove a message handler from the list of message handlers. Must
+  // not be called from a message handler (i.e. while a message is
+  // being processed).
+  void RemoveMessageHandler(MessageHandler* message_handler);
 
  private:
   class Launcher;
@@ -161,10 +168,9 @@ class ServiceProcessControl : public IPC::Channel::Sender,
   // Callback that gets invoked when a status message is received from
   // the cloud print proxy.
   scoped_ptr<Callback2<bool, std::string>::Type> cloud_print_status_callback_;
-  scoped_ptr<GetRemotingHostStatusCallback> remoting_host_status_callback_;
 
   // Handler for messages from service process.
-  MessageHandler* message_handler_;
+  std::set<MessageHandler*> message_handlers_;
 
   NotificationRegistrar registrar_;
 };
diff --git a/chrome/browser/service/service_process_control_browsertest.cc b/chrome/browser/service/service_process_control_browsertest.cc
index 8cf596c..519c005 100644
--- a/chrome/browser/service/service_process_control_browsertest.cc
+++ b/chrome/browser/service/service_process_control_browsertest.cc
@@ -72,7 +72,7 @@ class ServiceProcessControlBrowserTest
         service_pid,
         base::kProcessAccessWaitForTermination,
         &service_process_handle_));
-    process()->SetMessageHandler(this);
+    process()->AddMessageHandler(this);
     // Quit the current message. Post a QuitTask instead of just calling Quit()
     // because this can get invoked in the context of a Launch() call and we
     // may not be in Run() yet.
@@ -90,6 +90,10 @@ class ServiceProcessControlBrowserTest
     MessageLoop::current()->Quit();
   }
 
+  virtual void OnRemotingHostInfo(
+      const remoting::ChromotingHostInfo& host_info) {
+  }
+
   ServiceProcessControl* process() { return process_; }
 
  private: