Introduce background Download process to android

content/browser/android/child_process_launcher_android.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_ANDROID_CHILD_PROCESS_LAUNCHER_ANDROID_H_
 #define CONTENT_BROWSER_ANDROID_CHILD_PROCESS_LAUNCHER_ANDROID_H_
 
 #include <jni.h>
 #include <map>
 
@@ skipping 11 matching lines @@
 // ActivityManager.
 // The created process handle is returned to the |callback| on success, 0 is
 // returned if the process could not be created.
 void StartChildProcess(
     const base::CommandLine::StringVector& argv,
     int child_process_id,
     const scoped_ptr<FileDescriptorInfo> files_to_register,
     const std::map<int, base::MemoryMappedFile::Region>& regions,
     const StartChildProcessCallback& callback);
 
+// Starts the background download process if it hasn't been started.
+// TODO(qinmin): pass the download parameters here and pass it to java side.
+void StartDownloadProcessIfNecessary();
+
 // Stops a child process based on the handle returned form
 // StartChildProcess.
 void StopChildProcess(base::ProcessHandle handle);
 
 bool IsChildProcessOomProtected(base::ProcessHandle handle);
 
 void SetChildProcessInForeground(base::ProcessHandle handle,
                                  bool in_foreground);
 
 void RegisterViewSurface(int surface_id, jobject j_surface);
 
 void UnregisterViewSurface(int surface_id);
 
 void CreateSurfaceTextureSurface(int surface_texture_id,
                                  int client_id,
                                  gfx::SurfaceTexture* surface_texture);
 
 void DestroySurfaceTextureSurface(int surface_texture_id, int client_id);
 
 gfx::ScopedJavaSurface GetSurfaceTextureSurface(int surface_texture_id,
                                                 int client_id);
 
 bool RegisterChildProcessLauncher(JNIEnv* env);
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_ANDROID_CHILD_PROCESS_LAUNCHER_ANDROID_H_