Re-fix http://crbug.com/87176, and add a test.

content/browser/child_process_launcher.h

 // Copyright (c) 2012 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 CONTENT_BROWSER_CHILD_PROCESS_LAUNCHER_H_
 #define CONTENT_BROWSER_CHILD_PROCESS_LAUNCHER_H_
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/process_util.h"
 #include "content/common/content_export.h"
 
 class CommandLine;
 
 namespace content {
 class SandboxedProcessLauncherDelegate;
 
 // Launches a process asynchronously and notifies the client of the process
 // handle when it's available.  It's used to avoid blocking the calling thread
 // on the OS since often it can take > 100 ms to create the process.
+//
+// Call NewChildProcessLauncher to get the default implementation,
+// which launches a real process.
 class CONTENT_EXPORT ChildProcessLauncher {
  public:
   class CONTENT_EXPORT Client {
    public:
     // Will be called on the thread that the ChildProcessLauncher was
     // constructed on.
     virtual void OnProcessLaunched() = 0;
 
    protected:
     virtual ~Client() {}
   };
 
-  // Launches the process asynchronously, calling the client when the result is
-  // ready.  Deleting this object before the process is created is safe, since
-  // the callback won't be called.  If the process is still running by the time
-  // this object destructs, it will be terminated.
-  // Takes ownership of cmd_line.
-  ChildProcessLauncher(
-#if defined(OS_WIN)
-      SandboxedProcessLauncherDelegate* delegate,
-#elif defined(OS_POSIX)
-      bool use_zygote,
-      const base::EnvironmentVector& environ,
-      int ipcfd,
-#endif
-      CommandLine* cmd_line,
-      int child_process_id,
-      Client* client);
-  ~ChildProcessLauncher();
+  virtual ~ChildProcessLauncher();
 
   // True if the process is being launched and so the handle isn't available.
-  bool IsStarting();
+  virtual bool IsStarting() = 0;
 
   // Getter for the process handle.  Only call after the process has started.
-  base::ProcessHandle GetHandle();
+  virtual base::ProcessHandle GetHandle() = 0;
 
   // Call this when the child process exits to know what happened to it.
   // |known_dead| can be true if we already know the process is dead as it can
   // help the implemention figure the proper TerminationStatus.
   // |exit_code| is the exit code of the process if it exited (e.g. status from
   // waitpid if on posix, from GetExitCodeProcess on Windows). |exit_code| may
   // be NULL.
-  base::TerminationStatus GetChildTerminationStatus(bool known_dead,
-                                                    int* exit_code);
+  virtual base::TerminationStatus GetChildTerminationStatus(bool known_dead,
+                                                            int* exit_code) = 0;
 
   // Changes whether the process runs in the background or not.  Only call
   // this after the process has started.
-  void SetProcessBackgrounded(bool background);
+  virtual void SetProcessBackgrounded(bool background) = 0;
 
   // Controls whether the child process should be terminated on browser
   // shutdown.
-  void SetTerminateChildOnShutdown(bool terminate_on_shutdown);
+  virtual void SetTerminateChildOnShutdown(bool terminate_on_shutdown) = 0;
+};
 
- private:
-  class Context;
-
-  scoped_refptr<Context> context_;
-
-  DISALLOW_COPY_AND_ASSIGN(ChildProcessLauncher);
-};
+// Launches the process asynchronously, calling the client when the result is
+// ready.  Deleting this object before the process is created is safe, since
+// the callback won't be called.  If the process is still running by the time
+// this object destructs, it will be terminated.
+// Takes ownership of cmd_line.
+scoped_ptr<ChildProcessLauncher> NewChildProcessLauncher(

[Matt Perry, 2013/06/06 21:01:27]

nit: I generally prefer factory methods like this to be static methods on the
class

[Jeffrey Yasskin, 2013/06/06 21:06:56]

I have no problem with doing this, but I'd like jam or creis to endorse the
renaming first (and maybe pick a spelling), since it's in their API.

+#if defined(OS_WIN)
+    SandboxedProcessLauncherDelegate* delegate,
+#elif defined(OS_POSIX)
+    bool use_zygote,
+    const base::EnvironmentVector& environ,
+    int ipcfd,
+#endif
+    CommandLine* cmd_line,
+    int child_process_id,
+    ChildProcessLauncher::Client* client);
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_CHILD_PROCESS_LAUNCHER_H_