Introduce background Download process to android

content/public/common/process_type.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_PUBLIC_COMMON_PROCESS_TYPE_H_
 #define CONTENT_PUBLIC_COMMON_PROCESS_TYPE_H_
 
 #include <string>
 
+#include "build/build_config.h"
 #include "content/common/content_export.h"
 
 namespace content {
 
 // Defines the different process types.
 // NOTE: Do not remove or reorder the elements in this enum, and only add new
 // items at the end, right before PROCESS_TYPE_MAX. We depend on these specific
 // values in histograms.
 enum ProcessType {
   PROCESS_TYPE_UNKNOWN = 1,
   PROCESS_TYPE_BROWSER,
   PROCESS_TYPE_RENDERER,
   PROCESS_TYPE_PLUGIN,
   PROCESS_TYPE_WORKER_DEPRECATED,
   PROCESS_TYPE_UTILITY,
   PROCESS_TYPE_ZYGOTE,
   PROCESS_TYPE_SANDBOX_HELPER,
   PROCESS_TYPE_GPU,
   PROCESS_TYPE_PPAPI_PLUGIN,
   PROCESS_TYPE_PPAPI_BROKER,
+#if defined(OS_ANDROID)
+  PROCESS_TYPE_DOWNLOAD,

[svaldez, 2016/01/25 15:33:43]

I believe we aren't allowed to ifdef here, since otherwise the numbering for
histograms between Android and Desktop would be off.

[qinmin, 2016/01/25 22:48:23]

Done.

+#endif
   // Custom process types used by the embedder should start from here.
   PROCESS_TYPE_CONTENT_END,
   // If any embedder has more than 10 custom process types, update this.
   // We can switch to getting it from ContentClient, but that seems like
   // overkill at this time.
   PROCESS_TYPE_MAX = PROCESS_TYPE_CONTENT_END + 10,
 };
 
 // Returns an English name of the process type, should only be used for non
 // user-visible strings, or debugging pages like about:memory.
 CONTENT_EXPORT std::string GetProcessTypeNameInEnglish(int type);
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_COMMON_PROCESS_TYPE_H_