ExtensionUpdater: Abstract ExtensionDownloader creation

chrome/browser/extensions/updater/extension_updater.cc

Index: chrome/browser/extensions/updater/extension_updater.cc
diff --git a/chrome/browser/extensions/updater/extension_updater.cc b/chrome/browser/extensions/updater/extension_updater.cc
index e4843d134026f8c8ba4f02579eb10fdef84232c1..1c64bc9bb74f59401e14b8aa2fbe7837b7224da2 100644
--- a/chrome/browser/extensions/updater/extension_updater.cc
+++ b/chrome/browser/extensions/updater/extension_updater.cc
@@ -20,7 +20,6 @@
 #include "chrome/browser/extensions/crx_installer.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/pending_extension_manager.h"
-#include "chrome/browser/extensions/updater/extension_downloader.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/pref_names.h"
 #include "content/public/browser/browser_thread.h"
@@ -136,10 +135,11 @@ ExtensionUpdater::ExtensionUpdater(
     Profile* profile,
     int frequency_seconds,
     ExtensionCache* cache,
-    scoped_ptr<IdentityProvider> webstore_identity_provider)
+    const ExtensionDownloader::Factory& downloader_factory)
     : alive_(false),
       weak_ptr_factory_(this),
       service_(service),
+      downloader_factory_(downloader_factory),
       frequency_seconds_(frequency_seconds),
       will_check_soon_(false),
       extension_prefs_(extension_prefs),
@@ -148,8 +148,7 @@ ExtensionUpdater::ExtensionUpdater(
       next_request_id_(0),
       extension_registry_observer_(this),
       crx_install_is_running_(false),
-      extension_cache_(cache),
-      webstore_identity_provider_(webstore_identity_provider.release()) {
+      extension_cache_(cache) {
   DCHECK_GE(frequency_seconds_, 5);
   DCHECK_LE(frequency_seconds_, kMaxUpdateFrequencySeconds);
 #if defined(NDEBUG)
@@ -165,6 +164,12 @@ ExtensionUpdater::~ExtensionUpdater() {
   Stop();
 }
 
+void ExtensionUpdater::EnsureDownloaderCreated() {
+  if (!downloader_.get()) {
+    downloader_ = downloader_factory_.Run(this);
+  }
+}
+
 // The overall goal here is to balance keeping clients up to date while
 // avoiding a thundering herd against update servers.
 TimeDelta ExtensionUpdater::DetermineFirstCheckDelay() {
@@ -342,12 +347,7 @@ void ExtensionUpdater::CheckNow(const CheckParams& params) {
   request.callback = params.callback;
   request.install_immediately = params.install_immediately;
 
-  if (!downloader_.get()) {
-    downloader_.reset(
-        new ExtensionDownloader(this,
-                                profile_->GetRequestContext(),
-                                webstore_identity_provider_.get()));
-  }
+  EnsureDownloaderCreated();
 
   // Add fetch records for extensions that should be fetched by an update URL.
   // These extensions are not yet installed. They come from group policy