[Chromoting] Refactored worker process launching code and speeded up the desktop process launch.

remoting/host/win/unprivileged_process_delegate.h

Index: remoting/host/win/unprivileged_process_delegate.h
diff --git a/remoting/host/win/unprivileged_process_delegate.h b/remoting/host/win/unprivileged_process_delegate.h
index f256c6fbfb5bf83f93257a44a61cbf2959d417bb..230da6ebe36ad81a5e7b0212547938601813af4c 100644
--- a/remoting/host/win/unprivileged_process_delegate.h
+++ b/remoting/host/win/unprivileged_process_delegate.h
@@ -10,7 +10,9 @@
 #include "base/files/file_path.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/threading/non_thread_safe.h"
 #include "base/win/scoped_handle.h"
+#include "ipc/ipc_listener.h"
 #include "remoting/host/win/worker_process_launcher.h"
 
 class CommandLine;
@@ -21,7 +23,6 @@ class SingleThreadTaskRunner;
 
 namespace IPC {
 class ChannelProxy;
-class Listener;
 class Message;
 } // namespace IPC
 
@@ -29,29 +30,30 @@ namespace remoting {
 
 // Implements logic for launching and monitoring a worker process under a less
 // privileged user account.
-class UnprivilegedProcessDelegate : public WorkerProcessLauncher::Delegate {
+class UnprivilegedProcessDelegate
+    : public base::NonThreadSafe,
+      public IPC::Listener,
+      public WorkerProcessLauncher::Delegate {
  public:
   UnprivilegedProcessDelegate(
-      scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
       scoped_refptr<base::SingleThreadTaskRunner> io_task_runner,
       scoped_ptr<CommandLine> target_command);
   virtual ~UnprivilegedProcessDelegate();
 
-  // IPC::Sender implementation.
-  virtual bool Send(IPC::Message* message) OVERRIDE;
-
   // WorkerProcessLauncher::Delegate implementation.
+  virtual void LaunchProcess(WorkerProcessLauncher* event_handler) OVERRIDE;
+  virtual void Send(IPC::Message* message) OVERRIDE;
   virtual void CloseChannel() OVERRIDE;
-  virtual DWORD GetProcessId() const OVERRIDE;
-  virtual bool IsPermanentError(int failure_count) const OVERRIDE;
-  virtual void KillProcess(DWORD exit_code) OVERRIDE;
-  virtual bool LaunchProcess(
-      IPC::Listener* delegate,
-      base::win::ScopedHandle* process_exit_event_out) OVERRIDE;
+  virtual void KillProcess() OVERRIDE;
 
  private:
-  // The task runner all public methods of this class should be called on.
-  scoped_refptr<base::SingleThreadTaskRunner> main_task_runner_;
+  // IPC::Listener implementation.
+  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
+  virtual void OnChannelConnected(int32 peer_pid) OVERRIDE;
+  virtual void OnChannelError() OVERRIDE;
+
+  void ReportFatalError();
+  void ReportProcessLaunched(base::win::ScopedHandle worker_process);
 
   // The task runner serving job object notifications.
   scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
@@ -63,6 +65,8 @@ class UnprivilegedProcessDelegate : public WorkerProcessLauncher::Delegate {
   // process.
   scoped_ptr<IPC::ChannelProxy> channel_;
 
+  WorkerProcessLauncher* event_handler_;
+
   // The handle of the worker process, if launched.
   base::win::ScopedHandle worker_process_;