Hold cros_component_installers in browser_process.

chrome/browser/browser_process.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.
 
 // This interface is for managing the global services of the application. Each
 // service is lazily created when requested the first time. The service getters
 // will return NULL if the service is not available, so callers must check for
 // this condition.
 
 #ifndef CHROME_BROWSER_BROWSER_PROCESS_H_
@@ skipping 36 matching lines @@
 
 namespace subresource_filter {
 class ContentRulesetService;
 }
 
 namespace variations {
 class VariationsService;
 }
 
 namespace component_updater {
+class ComponentInstallerTraits;
 class ComponentUpdateService;
+class DefaultComponentInstaller;
 class PnaclComponentInstaller;
 class SupervisedUserWhitelistInstaller;
 }
 
 namespace extensions {
 class EventRouterForwarder;
 }
 
 namespace gcm {
 class GCMDriver;
@@ skipping 187 matching lines @@
 
   virtual net_log::ChromeNetLog* net_log() = 0;
 
   virtual component_updater::ComponentUpdateService* component_updater() = 0;
 
   virtual CRLSetFetcher* crl_set_fetcher() = 0;
 
   virtual component_updater::PnaclComponentInstaller*
   pnacl_component_installer() = 0;
 
+#if defined(OS_CHROMEOS)
+  virtual component_updater::DefaultComponentInstaller*

[waffles, 2017/05/23 20:40:14]

I think you actually want to return the Traits object. Having the DCI won't help
you much.
Also, can we return a const reference (or at least a smart pointer)?

[xiaochu, 2017/05/23 21:31:59]

Done.

Thanks for pointing this out. I just realized installer does not have function
to return manifest. I save installer here because it holds all the data about
component in memory (in addition to manifest and traits). 

+  cros_component_installer(
+      const std::string& name,
+      std::unique_ptr<component_updater::ComponentInstallerTraits>
+          installer_traits) = 0;
+#endif
+
   virtual component_updater::SupervisedUserWhitelistInstaller*
   supervised_user_whitelist_installer() = 0;
 
   virtual MediaFileSystemRegistry* media_file_system_registry() = 0;
 
   virtual bool created_local_state() const = 0;
 
 #if BUILDFLAG(ENABLE_WEBRTC)
   virtual WebRtcLogUploader* webrtc_log_uploader() = 0;
 #endif
@@ skipping 14 matching lines @@
   // Returns the Physical Web data source.
   virtual physical_web::PhysicalWebDataSource* GetPhysicalWebDataSource() = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(BrowserProcess);
 };
 
 extern BrowserProcess* g_browser_process;
 
 #endif  // CHROME_BROWSER_BROWSER_PROCESS_H_