Introduce background Download process to android

content/app/content_main_runner.cc

Index: content/app/content_main_runner.cc
diff --git a/content/app/content_main_runner.cc b/content/app/content_main_runner.cc
index 037c79bd512ed948ee71b560b89076cdbf2300fb..52b6f0baab36e1e232ac0b805ff66598e8a432bc 100644
--- a/content/app/content_main_runner.cc
+++ b/content/app/content_main_runner.cc
@@ -132,6 +132,9 @@ extern int PpapiBrokerMain(const MainFunctionParams&);
 #endif
 extern int RendererMain(const content::MainFunctionParams&);
 extern int UtilityMain(const MainFunctionParams&);
+#if defined(OS_ANDROID)
+extern int DownloadMain(const MainFunctionParams&);
+#endif
 }  // namespace content
 
 namespace content {
@@ -358,6 +361,9 @@ int RunNamedProcessTypeMain(
     { switches::kUtilityProcess,     UtilityMain },
     { switches::kRendererProcess,    RendererMain },
     { switches::kGpuProcess,         GpuMain },
+#if defined(OS_ANDROID)
+    { switches::kDownloadProcess,    DownloadMain},
+#endif
 #endif  // !CHROME_MULTIPLE_DLL_BROWSER
   };