Add best-effort/allow rollback flags on WorkItem.

chrome/installer/util/work_item.cc

Index: chrome/installer/util/work_item.cc
diff --git a/chrome/installer/util/work_item.cc b/chrome/installer/util/work_item.cc
index e38413d94ef34df56a274cf864eab751493fbb96..f29d7f8d3c42db01f871a8a07102c86abc9f5d62 100644
--- a/chrome/installer/util/work_item.cc
+++ b/chrome/installer/util/work_item.cc
@@ -19,11 +19,8 @@
 #include "chrome/installer/util/set_reg_value_work_item.h"
 #include "chrome/installer/util/work_item_list.h"
 
-WorkItem::WorkItem() : ignore_failure_(false) {
-}
-
-WorkItem::~WorkItem() {
-}
+WorkItem::WorkItem() = default;
+WorkItem::~WorkItem() = default;
 
 CallbackWorkItem* WorkItem::CreateCallbackWorkItem(
     base::Callback<bool(const CallbackWorkItem&)> callback) {
@@ -162,3 +159,17 @@ WorkItemList* WorkItem::CreateNoRollbackWorkItemList() {
 WorkItemList* WorkItem::CreateConditionalWorkItemList(Condition* condition) {
   return new ConditionalWorkItemList(condition);
 }
+
+bool WorkItem::Do() {
+  DCHECK_EQ(BEFORE_DO, state_);
+  const bool success = DoImpl();
+  state_ = AFTER_DO;
+  return best_effort() ? true : success;
+}
+
+void WorkItem::Rollback() {
+  DCHECK_EQ(AFTER_DO, state_);
+  if (allow_rollback())
+    RollbackImpl();
+  state_ = AFTER_ROLLBACK;
+}