Use service process to collect printers.

chrome/browser/service_process/service_process_control.h

Index: chrome/browser/service_process/service_process_control.h
diff --git a/chrome/browser/service_process/service_process_control.h b/chrome/browser/service_process/service_process_control.h
index eedd4a3fd074b2cb328d144fb396be6c376db85b..9db9324f84376196af2e8d97ffbde3b086307219 100644
--- a/chrome/browser/service_process/service_process_control.h
+++ b/chrome/browser/service_process/service_process_control.h
@@ -60,13 +60,17 @@ class ServiceProcessControl : public IPC::Sender,
     SERVICE_EVENT_INFO_REPLY,
     SERVICE_EVENT_HISTOGRAMS_REQUEST,
     SERVICE_EVENT_HISTOGRAMS_REPLY,
+    SERVICE_PRINTERS_REQUEST,
+    SERVICE_PRINTERS_REPLY,
     SERVICE_EVENT_MAX,
   };
 
   typedef IDMap<ServiceProcessControl>::iterator iterator;
   typedef std::queue<IPC::Message> MessageQueue;
   typedef base::Callback<void(const cloud_print::CloudPrintProxyInfo&)>
-      CloudPrintProxyInfoHandler;
+      CloudPrintProxyInfoCallback;
+  typedef base::Callback<void(const std::vector<std::string>&)>
+      PrintersCallback;
 
   // Returns the singleton instance of this class.
   static ServiceProcessControl* GetInstance();
@@ -118,7 +122,7 @@ class ServiceProcessControl : public IPC::Sender,
   // reply from service. The method resets any previous callback.
   // This call starts service if needed.
   bool GetCloudPrintProxyInfo(
-      const CloudPrintProxyInfoHandler& cloud_print_status_callback);
+      const CloudPrintProxyInfoCallback& cloud_print_status_callback);
 
   // Send request for histograms collected in service process.
   // Returns true if request was sent, and callback will be called in case of
@@ -128,6 +132,13 @@ class ServiceProcessControl : public IPC::Sender,
   bool GetHistograms(const base::Closure& cloud_print_status_callback,
                      const base::TimeDelta& timeout);
 
+  // Send request for printers available for cloud print proxy.
+  // The callback gets the information when received.
+  // Returns true if request was sent. Callback will be called only in case of
+  // reply from service. The method resets any previous callback.
+  // This call starts service if needed.
+  bool GetPrinters(const PrintersCallback& enumerate_printers_callback);
+
  private:
   // This class is responsible for launching the service process on the
   // PROCESS_LAUNCHER thread.
@@ -175,6 +186,7 @@ class ServiceProcessControl : public IPC::Sender,
   void OnCloudPrintProxyInfo(
       const cloud_print::CloudPrintProxyInfo& proxy_info);
   void OnHistograms(const std::vector<std::string>& pickled_histograms);
+  void OnPrinters(const std::vector<std::string>& printers);
 
   // Runs callback provided in |GetHistograms()|.
   void RunHistogramsCallback();
@@ -204,9 +216,13 @@ class ServiceProcessControl : public IPC::Sender,
   // Callbacks that get invoked when there was a connection failure.
   TaskList connect_failure_tasks_;
 
+  // Callback that gets invoked when a printers is received from
+  // the cloud print proxy.
+  PrintersCallback printers_callback_;
+
   // Callback that gets invoked when a status message is received from
   // the cloud print proxy.
-  CloudPrintProxyInfoHandler cloud_print_info_callback_;
+  CloudPrintProxyInfoCallback cloud_print_info_callback_;
 
   // Callback that gets invoked when a message with histograms is received from
   // the service process.