Factor Chrome details out of update manifest fetching.

chrome/browser/extensions/updater/extension_downloader.h

Index: chrome/browser/extensions/updater/extension_downloader.h
diff --git a/chrome/browser/extensions/updater/extension_downloader.h b/chrome/browser/extensions/updater/extension_downloader.h
index a0409866f17938dfcfb8bd9594de7fe2cfbce0b9..ff9547825ed580b5b3322a55dc42999d0ff82b00 100644
--- a/chrome/browser/extensions/updater/extension_downloader.h
+++ b/chrome/browser/extensions/updater/extension_downloader.h
@@ -19,8 +19,8 @@
 #include "base/memory/weak_ptr.h"
 #include "base/version.h"
 #include "chrome/browser/extensions/updater/extension_downloader_delegate.h"
-#include "chrome/browser/extensions/updater/manifest_fetch_data.h"
 #include "chrome/browser/extensions/updater/request_queue.h"
+#include "extensions/browser/updater/manifest_fetch_data.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/update_manifest.h"
 #include "google_apis/gaia/oauth2_token_service.h"
@@ -47,6 +47,7 @@ struct UpdateDetails {
 
 class ExtensionCache;
 class ExtensionUpdaterTest;
+class ManifestFetchDataDelegate;
 
 // A class that checks for updates of a given list of extensions, and downloads
 // the crx file when updates are found. It uses a |ExtensionDownloaderDelegate|
@@ -100,6 +101,10 @@ class ExtensionDownloader
   void SetWebstoreIdentityProvider(
       scoped_ptr<IdentityProvider> identity_provider);
 
+  // Sets a new delegate for update manifest fetches.
+  void SetManifestFetchDataDelegate(
+      scoped_ptr<ManifestFetchDataDelegate> delegate);
+
   // These are needed for unit testing, to help identify the correct mock
   // URLFetcher objects.
   static const int kManifestFetcherId = 1;
@@ -291,6 +296,9 @@ class ExtensionDownloader
   // A pending token fetch request.
   scoped_ptr<OAuth2TokenService::Request> access_token_request_;
 
+  // A delegate which controls details related to update manifest retrieval.
+  scoped_ptr<ManifestFetchDataDelegate> manifest_fetch_data_delegate_;
+
   DISALLOW_COPY_AND_ASSIGN(ExtensionDownloader);
 };