Hold cros_component_installers in browser_process.

chrome/browser/browser_process_platform_part_chromeos.cc

 // Copyright (c) 2013 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.
 
 #include "chrome/browser/browser_process_platform_part_chromeos.h"
 
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/time/default_tick_clock.h"
 #include "base/time/tick_clock.h"
@@ skipping 141 matching lines @@
 
 void BrowserProcessPlatformPart::DestroySystemClock() {
   system_clock_.reset();
 }
 
 void BrowserProcessPlatformPart::CreateProfileHelper() {
   DCHECK(!created_profile_helper_ && !profile_helper_);
   created_profile_helper_ = true;
   profile_helper_.reset(new chromeos::ProfileHelper());
 }
+
+scoped_refptr<component_updater::DefaultComponentInstaller>

[sky, 2017/05/23 23:20:29]

Style guide says position definition and declaration position should match (in
other words, move this above CreateProfileHelper).

[xiaochu, 2017/05/23 23:40:52]

Done.

+BrowserProcessPlatformPart::GetCrosComponentInstaller(
+    const std::string& name,
+    std::unique_ptr<component_updater::ComponentInstallerTraits>
+        installer_traits) {
+  auto it = cros_component_installers_.find(name);
+  if (it == cros_component_installers_.end()) {
+    cros_component_installers_[name] =
+        new component_updater::DefaultComponentInstaller(
+            std::move(installer_traits));
+  }
+  return cros_component_installers_[name];
+}