Remove all the browser side extensions code from Android.

chrome/browser/prefs/browser_prefs.cc

Index: chrome/browser/prefs/browser_prefs.cc
diff --git a/chrome/browser/prefs/browser_prefs.cc b/chrome/browser/prefs/browser_prefs.cc
index fbb5fa3a650ae84fa435d0cbf5473488dc18eb58..c154d9b37b7f5520124d3d7d262a852e54b17fff 100644
--- a/chrome/browser/prefs/browser_prefs.cc
+++ b/chrome/browser/prefs/browser_prefs.cc
@@ -23,7 +23,6 @@
 #include "chrome/browser/custom_handlers/protocol_handler_registry.h"
 #include "chrome/browser/devtools/devtools_window.h"
 #include "chrome/browser/download/download_prefs.h"
-#include "chrome/browser/extensions/extension_web_ui.h"
 #include "chrome/browser/external_protocol/external_protocol_handler.h"
 #include "chrome/browser/first_run/first_run.h"
 #include "chrome/browser/geolocation/geolocation_prefs.h"
@@ -95,7 +94,6 @@
 #include "components/sync_driver/sync_prefs.h"
 #include "components/translate/core/browser/translate_prefs.h"
 #include "content/public/browser/render_process_host.h"
-#include "extensions/browser/extension_prefs.h"
 #include "net/http/http_server_properties_manager.h"
 
 #if defined(ENABLE_AUTOFILL_DIALOG)
@@ -113,8 +111,10 @@
 #include "chrome/browser/extensions/activity_log/activity_log.h"
 #include "chrome/browser/extensions/api/commands/command_service.h"
 #include "chrome/browser/extensions/api/tabs/tabs_api.h"
+#include "chrome/browser/extensions/extension_web_ui.h"
 #include "chrome/browser/extensions/launch_util.h"
 #include "chrome/browser/signin/easy_unlock_service.h"
+#include "extensions/browser/extension_prefs.h"
 #endif
 
 #if defined(ENABLE_MANAGED_USERS)
@@ -406,11 +406,9 @@ void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry) {
   EasyUnlockService::RegisterProfilePrefs(registry);
   extensions::ActivityLog::RegisterProfilePrefs(registry);
   extensions::launch_util::RegisterProfilePrefs(registry);
-#endif
-  // TODO(thestig) These should be in ifdef'd out, but too many parts of Chrome
-  // still expects it to be registered.
   ExtensionWebUI::RegisterProfilePrefs(registry);
   extensions::ExtensionPrefs::RegisterProfilePrefs(registry);
+#endif
 
 #if defined(ENABLE_FULL_PRINTING)
   print_dialog_cloud::RegisterProfilePrefs(registry);