Added support for multiple urls in the component updater.

chrome/browser/component_updater/component_updater_utils.h

Index: chrome/browser/component_updater/component_updater_utils.h
diff --git a/chrome/browser/component_updater/component_updater_utils.h b/chrome/browser/component_updater/component_updater_utils.h
index 043bd76c9add41d90397cca61117f43ac1cb12a1..67aa0d18632195995783d79edf3eefb354a19757 100644
--- a/chrome/browser/component_updater/component_updater_utils.h
+++ b/chrome/browser/component_updater/component_updater_utils.h
@@ -21,6 +21,8 @@ class URLRequestContextGetter;
 
 namespace component_updater {
 
+struct CrxUpdateItem;
+
 // An update protocol request starts with a common preamble which includes
 // version and platform information for Chrome and the operating system,
 // followed by a request body, which is the actual payload of the request.
@@ -60,6 +62,9 @@ bool FetchSuccess(const net::URLFetcher& fetcher);
 // fetch is pending or canceled.
 int GetFetchError(const net::URLFetcher& fetcher);
 
+// Returns true if the |update_item| contains a valid differential update url.
+bool HasDiffUpdate(const CrxUpdateItem* update_item);
+
 // Returns true if the |status_code| represents a server error 5xx.
 bool IsHttpServerError(int status_code);