Use ServiceIPCServer::MessageHandler in CloudPrintMessageHandler.

* Moves cloud print IPC message handling from ServiceIPCServer to CloudPrintMessageHandler
* Removes the last 4 uses of g_service_process from ServiceIPCServer.
* Add unit test for ServiceIPCServer

BUG=402456

Review URL: https://codereview.chromium.org/1249513003

Cr-Commit-Position: refs/heads/master@{#340664}

chrome/chrome.gyp

@@ -741,6 +741,8 @@
             'service/cloud_print/cloud_print_auth.h',
             'service/cloud_print/cloud_print_connector.cc',
             'service/cloud_print/cloud_print_connector.h',
+            'service/cloud_print/cloud_print_message_handler.cc',
+            'service/cloud_print/cloud_print_message_handler.h',
             'service/cloud_print/cloud_print_proxy.cc',
             'service/cloud_print/cloud_print_proxy.h',
             'service/cloud_print/cloud_print_proxy_backend.cc',

chrome/chrome_tests_unit.gypi

@@ -1093,6 +1093,7 @@
       'service/cloud_print/connector_settings_unittest.cc',
       'service/cloud_print/printer_job_handler_unittest.cc',
       'service/cloud_print/printer_job_queue_handler_unittest.cc',
+      'service/service_ipc_server_unittest.cc',
       'service/service_process_prefs_unittest.cc',
     ],
     'chrome_unit_tests_captive_portal_sources': [

chrome/service/BUILD.gn

@@ -12,6 +12,8 @@ static_library("service") {
     "cloud_print/cloud_print_auth.h",
     "cloud_print/cloud_print_connector.cc",
     "cloud_print/cloud_print_connector.h",
+    "cloud_print/cloud_print_message_handler.cc",
+    "cloud_print/cloud_print_message_handler.h",
     "cloud_print/cloud_print_proxy.cc",
     "cloud_print/cloud_print_proxy.h",
     "cloud_print/cloud_print_proxy_backend.cc",

chrome/service/cloud_print/cloud_print_message_handler.cc

@@ -0,0 +1,65 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/service/cloud_print/cloud_print_message_handler.h"
+
+#include <vector>
+
+#include "chrome/common/service_messages.h"
+#include "ipc/ipc_sender.h"
+
+namespace cloud_print {
+
+CloudPrintMessageHandler::CloudPrintMessageHandler(
+    IPC::Sender* ipc_sender,
+    CloudPrintProxy::Provider* proxy_provider)
+    : ipc_sender_(ipc_sender), proxy_provider_(proxy_provider) {
+  DCHECK(ipc_sender);
+  DCHECK(proxy_provider);
+}
+
+CloudPrintMessageHandler::~CloudPrintMessageHandler() {
+}
+
+bool CloudPrintMessageHandler::HandleMessage(const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(CloudPrintMessageHandler, message)
+    IPC_MESSAGE_HANDLER(ServiceMsg_EnableCloudPrintProxyWithRobot,
+                        OnEnableCloudPrintProxyWithRobot)
+    IPC_MESSAGE_HANDLER(ServiceMsg_DisableCloudPrintProxy,
+                        OnDisableCloudPrintProxy)
+    IPC_MESSAGE_HANDLER(ServiceMsg_GetCloudPrintProxyInfo,
+                        OnGetCloudPrintProxyInfo)
+    IPC_MESSAGE_HANDLER(ServiceMsg_GetPrinters, OnGetPrinters)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
+void CloudPrintMessageHandler::OnEnableCloudPrintProxyWithRobot(
+    const std::string& robot_auth_code,
+    const std::string& robot_email,
+    const std::string& user_email,
+    const base::DictionaryValue& user_settings) {
+  proxy_provider_->GetCloudPrintProxy()->EnableForUserWithRobot(
+      robot_auth_code, robot_email, user_email, user_settings);
+}
+
+void CloudPrintMessageHandler::OnGetCloudPrintProxyInfo() {
+  CloudPrintProxyInfo info;
+  proxy_provider_->GetCloudPrintProxy()->GetProxyInfo(&info);
+  ipc_sender_->Send(new ServiceHostMsg_CloudPrintProxy_Info(info));
+}
+
+void CloudPrintMessageHandler::OnGetPrinters() {
+  std::vector<std::string> printers;
+  proxy_provider_->GetCloudPrintProxy()->GetPrinters(&printers);
+  ipc_sender_->Send(new ServiceHostMsg_Printers(printers));
+}
+
+void CloudPrintMessageHandler::OnDisableCloudPrintProxy() {
+  proxy_provider_->GetCloudPrintProxy()->UnregisterPrintersAndDisableForUser();
+}
+
+}  // namespace cloud_print

chrome/service/cloud_print/cloud_print_message_handler.h

@@ -0,0 +1,54 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_SERVICE_CLOUD_PRINT_CLOUD_PRINT_MESSAGE_HANDLER_H_
+#define CHROME_SERVICE_CLOUD_PRINT_CLOUD_PRINT_MESSAGE_HANDLER_H_
+
+#include <string>
+
+#include "base/macros.h"
+#include "chrome/service/cloud_print/cloud_print_proxy.h"
+#include "chrome/service/service_ipc_server.h"
+
+namespace base {
+class DictionaryValue;
+}
+
+namespace IPC {
+class Message;
+class Sender;
+}
+
+namespace cloud_print {
+
+// Handles IPC messages for Cloud Print. Lives on the main thread.
+class CloudPrintMessageHandler : public ServiceIPCServer::MessageHandler {
+ public:
+  CloudPrintMessageHandler(IPC::Sender* ipc_sender,
+                           CloudPrintProxy::Provider* proxy_provider);
+  ~CloudPrintMessageHandler() override;
+
+  // ServiceIPCServer::MessageHandler implementation.
+  bool HandleMessage(const IPC::Message& message) override;
+
+ private:
+  // IPC message handlers.
+  void OnEnableCloudPrintProxyWithRobot(
+      const std::string& robot_auth_code,
+      const std::string& robot_email,
+      const std::string& user_email,
+      const base::DictionaryValue& user_settings);
+  void OnGetCloudPrintProxyInfo();
+  void OnGetPrinters();
+  void OnDisableCloudPrintProxy();
+
+  IPC::Sender* ipc_sender_;  // Owned by our owner.
+  CloudPrintProxy::Provider* proxy_provider_;  // Owned by our owner.
+
+  DISALLOW_COPY_AND_ASSIGN(CloudPrintMessageHandler);
+};
+
+}  // namespace cloud_print
+
+#endif  // CHROME_SERVICE_CLOUD_PRINT_CLOUD_PRINT_MESSAGE_HANDLER_H_

chrome/service/cloud_print/cloud_print_proxy.h

@@ -36,6 +36,12 @@ class CloudPrintProxy : public CloudPrintProxyFrontend,
   CloudPrintProxy();
   ~CloudPrintProxy() override;
 
+  // Provides a CloudPrintProxy instance, which may be lazily instantiated.
+  class Provider {
+   public:
+    virtual CloudPrintProxy* GetCloudPrintProxy() = 0;
+  };
+
   // Initializes the object. This should be called every time an object of this
   // class is constructed.
   void Initialize(ServiceProcessPrefs* service_prefs, Client* client);

chrome/service/service_ipc_server.cc

@@ -6,8 +6,6 @@
 
 #include "base/metrics/histogram_delta_serialization.h"
 #include "chrome/common/service_messages.h"
-#include "chrome/service/cloud_print/cloud_print_proxy.h"
-#include "chrome/service/service_process.h"
 #include "ipc/ipc_logging.h"
 
 ServiceIPCServer::ServiceIPCServer(
@@ -87,6 +85,10 @@ bool ServiceIPCServer::Send(IPC::Message* msg) {
   return channel_->Send(msg);
 }
 
+void ServiceIPCServer::AddMessageHandler(scoped_ptr<MessageHandler> handler) {
+  message_handlers_.push_back(handler.release());
+}
+
 bool ServiceIPCServer::OnMessageReceived(const IPC::Message& msg) {
   bool handled = true;
   // When we get a message, always mark the IPC client as connected. The
@@ -95,34 +97,23 @@ bool ServiceIPCServer::OnMessageReceived(const IPC::Message& msg) {
   // again on subsequent connections.
   ipc_client_connected_ = true;
   IPC_BEGIN_MESSAGE_MAP(ServiceIPCServer, msg)
-    IPC_MESSAGE_HANDLER(ServiceMsg_EnableCloudPrintProxyWithRobot,
-                        OnEnableCloudPrintProxyWithRobot)
-    IPC_MESSAGE_HANDLER(ServiceMsg_DisableCloudPrintProxy,
-                        OnDisableCloudPrintProxy)
-    IPC_MESSAGE_HANDLER(ServiceMsg_GetCloudPrintProxyInfo,
-                        OnGetCloudPrintProxyInfo)
     IPC_MESSAGE_HANDLER(ServiceMsg_GetHistograms, OnGetHistograms)
-    IPC_MESSAGE_HANDLER(ServiceMsg_GetPrinters, OnGetPrinters)
     IPC_MESSAGE_HANDLER(ServiceMsg_Shutdown, OnShutdown);
     IPC_MESSAGE_HANDLER(ServiceMsg_UpdateAvailable, OnUpdateAvailable);
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
-  return handled;
-}
 
-void ServiceIPCServer::OnEnableCloudPrintProxyWithRobot(
-    const std::string& robot_auth_code,
-    const std::string& robot_email,
-    const std::string& user_email,
-    const base::DictionaryValue& user_settings) {
-  g_service_process->GetCloudPrintProxy()->EnableForUserWithRobot(
-      robot_auth_code, robot_email, user_email, user_settings);
-}
+  if (!handled) {
+    // Make a copy of the handlers to prevent modification during iteration.
+    std::vector<MessageHandler*> temp_handlers = message_handlers_.get();
+    for (const auto& handler : temp_handlers) {
+      handled = handler->HandleMessage(msg);
+      if (handled)
+        break;
+    }
+  }
 
-void ServiceIPCServer::OnGetCloudPrintProxyInfo() {
-  cloud_print::CloudPrintProxyInfo info;
-  g_service_process->GetCloudPrintProxy()->GetProxyInfo(&info);
-  channel_->Send(new ServiceHostMsg_CloudPrintProxy_Info(info));
+  return handled;
 }
 
 void ServiceIPCServer::OnGetHistograms() {
@@ -135,19 +126,6 @@ void ServiceIPCServer::OnGetHistograms() {
   channel_->Send(new ServiceHostMsg_Histograms(deltas));
 }
 
-void ServiceIPCServer::OnGetPrinters() {
-  std::vector<std::string> printers;
-  g_service_process->GetCloudPrintProxy()->GetPrinters(&printers);
-  channel_->Send(new ServiceHostMsg_Printers(printers));
-}
-
-void ServiceIPCServer::OnDisableCloudPrintProxy() {
-  // User disabled CloudPrint proxy explicitly. Delete printers
-  // registered from this proxy and disable proxy.
-  g_service_process->GetCloudPrintProxy()->
-      UnregisterPrintersAndDisableForUser();
-}
-
 void ServiceIPCServer::OnShutdown() {
   client_->OnShutdown();
 }

chrome/service/service_ipc_server.h

@@ -5,18 +5,17 @@
 #ifndef CHROME_SERVICE_SERVICE_IPC_SERVER_H_
 #define CHROME_SERVICE_SERVICE_IPC_SERVER_H_
 
-#include <string>
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/scoped_vector.h"
 #include "ipc/ipc_channel_handle.h"
 #include "ipc/ipc_listener.h"
 #include "ipc/ipc_sync_channel.h"
 #include "ipc/ipc_sender.h"
 
 namespace base {
 
-class DictionaryValue;
 class HistogramDeltaSerialization;
 class WaitableEvent;
 
@@ -25,6 +24,13 @@ class WaitableEvent;
 // This class handles IPC commands for the service process.
 class ServiceIPCServer : public IPC::Listener, public IPC::Sender {
  public:
+  class MessageHandler {
+   public:
+    virtual ~MessageHandler() {}
+    // Must return true if the message is handled.
+    virtual bool HandleMessage(const IPC::Message& message) = 0;
+  };
+
   class Client {
    public:
     virtual ~Client() {}
@@ -52,9 +58,16 @@ class ServiceIPCServer : public IPC::Listener, public IPC::Sender {
   // IPC::Sender implementation.
   bool Send(IPC::Message* msg) override;
 
+  // Registers a MessageHandler with the ServiceIPCServer. When an IPC message
+  // is received that is not handled by the ServiceIPCServer itself, the
+  // handlers will be called to handle the message in first-add first-call order
+  // until it is handled or there are no more handlers.
+  void AddMessageHandler(scoped_ptr<MessageHandler> handler);
+
   bool is_ipc_client_connected() const { return ipc_client_connected_; }
 
  private:
+  friend class ServiceIPCServerTest;
   friend class MockServiceIPCServer;
 
   // IPC::Listener implementation.
@@ -63,16 +76,7 @@ class ServiceIPCServer : public IPC::Listener, public IPC::Sender {
   void OnChannelError() override;
 
   // IPC message handlers.
-  void OnEnableCloudPrintProxyWithRobot(
-      const std::string& robot_auth_code,
-      const std::string& robot_email,
-      const std::string& user_email,
-      const base::DictionaryValue& user_settings);
-  void OnGetCloudPrintProxyInfo();
   void OnGetHistograms();
-  void OnGetPrinters();
-  void OnDisableCloudPrintProxy();
-
   void OnShutdown();
   void OnUpdateAvailable();
 
@@ -84,6 +88,7 @@ class ServiceIPCServer : public IPC::Listener, public IPC::Sender {
   IPC::ChannelHandle channel_handle_;
   scoped_ptr<IPC::SyncChannel> channel_;
   base::WaitableEvent* shutdown_event_;
+  ScopedVector<MessageHandler> message_handlers_;
 
   // Indicates whether an IPC client is currently connected to the channel.
   bool ipc_client_connected_;