Add best-effort/allow rollback flags on WorkItem.

chrome/installer/util/work_item_list.cc

Index: chrome/installer/util/work_item_list.cc
diff --git a/chrome/installer/util/work_item_list.cc b/chrome/installer/util/work_item_list.cc
index 609933065afaa65ac768c1c48a34d0820e2b79ef..8dda5232dccac2651146121f87f5a1c49b455e66 100644
--- a/chrome/installer/util/work_item_list.cc
+++ b/chrome/installer/util/work_item_list.cc
@@ -32,9 +32,8 @@ WorkItemList::WorkItemList()
     : status_(ADD_ITEM) {
 }
 
-bool WorkItemList::Do() {
-  if (status_ != ADD_ITEM)
-    return false;
+bool WorkItemList::DoImpl() {
+  DCHECK_EQ(ADD_ITEM, status_);
 
   bool result = true;
   while (!list_.empty()) {
@@ -55,7 +54,7 @@ bool WorkItemList::Do() {
   return result;
 }
 
-void WorkItemList::Rollback() {
+void WorkItemList::RollbackImpl() {
   if (status_ != LIST_EXECUTED)
     return;
 
@@ -236,16 +235,15 @@ WorkItem* WorkItemList::AddSelfRegWorkItem(const std::wstring& dll_path,
 NoRollbackWorkItemList::~NoRollbackWorkItemList() {
 }
 
-bool NoRollbackWorkItemList::Do() {
-  if (status_ != ADD_ITEM)
-    return false;
+bool NoRollbackWorkItemList::DoImpl() {

[grt (UTC plus 2), 2016/04/27 17:29:17]

do we need this class? can WIL::DoImpl check its own allow_rollback and apply it
to the items in the list? same q for best_effort? this fn is a hybrid of
best_effort on |this| WorkItem + no rollback, but the best_effortness isn't
documented.

[fdoray, 2016/05/02 20:10:00]

Applying the WIL's allow_rollback/best_effort flag to the WorkItems in the list
makes sense.

NoRollbackWorkItem and WorkItemList+disable_rollback+best_effort are identical
except that WIL+disable_rollback+best_effort doesn't return false if one of its
WorkItems fails. Would it matter if we weren't able to log these errors [1] [2]?

[1]
https://code.google.com/p/chromium/codesearch#chromium/src/chrome/installer/s...
[2]
https://code.google.com/p/chromium/codesearch#chromium/src/chrome/installer/s...

[grt (UTC plus 2), 2016/05/06 18:39:13]

No. It'd be nice to have something like:

  VLOG(1) << "Beginning execution of work item list " << log_message();

at the top of WorkItemList::Do() so that we can easily see in verbose logs what
is about to happen, and then for each WIL creator to set a log_message on the
list.

+  DCHECK_EQ(ADD_ITEM, status_);
 
   bool result = true;
   while (!list_.empty()) {
     WorkItem* work_item = list_.front();
     list_.pop_front();
     executed_list_.push_front(work_item);
-    work_item->set_ignore_failure(true);
+    work_item->set_allow_rollback(false);
     if (!work_item->Do()) {
       LOG(ERROR) << "NoRollbackWorkItemList: item execution failed "
                  << work_item->log_message();
@@ -260,6 +258,6 @@ bool NoRollbackWorkItemList::Do() {
   return result;
 }
 
-void NoRollbackWorkItemList::Rollback() {
+void NoRollbackWorkItemList::RollbackImpl() {
   // Ignore rollback.
 }