Replace "external_install" boolean parameter with explicit enumeration in ExtensionUninstall method.

chrome/browser/sync/test/integration/sync_extension_helper.cc

Index: chrome/browser/sync/test/integration/sync_extension_helper.cc
diff --git a/chrome/browser/sync/test/integration/sync_extension_helper.cc b/chrome/browser/sync/test/integration/sync_extension_helper.cc
index 6ff393886ea5fb4efb238b28d9fdfe4952234476..7f51c713aa3aa254afc322e90c13be171105d7f1 100644
--- a/chrome/browser/sync/test/integration/sync_extension_helper.cc
+++ b/chrome/browser/sync/test/integration/sync_extension_helper.cc
@@ -82,7 +82,8 @@ void SyncExtensionHelper::UninstallExtension(
     Profile* profile, const std::string& name) {
   ExtensionService::UninstallExtensionHelper(
       extensions::ExtensionSystem::Get(profile)->extension_service(),
-      extensions::id_util::GenerateId(name));
+      extensions::id_util::GenerateId(name),
+      ExtensionService::UNINSTALL_REASON_SYNC);
 }
 
 std::vector<std::string> SyncExtensionHelper::GetInstalledExtensionNames(