Add best-effort/allow rollback flags on WorkItem.

chrome/installer/util/delete_tree_work_item.cc

Index: chrome/installer/util/delete_tree_work_item.cc
diff --git a/chrome/installer/util/delete_tree_work_item.cc b/chrome/installer/util/delete_tree_work_item.cc
index 7dbb9e7a618c0bef29ec83a89f4ba21e4dcddda7..61395c2cbe6b19bd955325f3d7336a93d8410c88 100644
--- a/chrome/installer/util/delete_tree_work_item.cc
+++ b/chrome/installer/util/delete_tree_work_item.cc
@@ -48,7 +48,7 @@ DeleteTreeWorkItem::~DeleteTreeWorkItem() {
 
 // We first try to move key_path_ to backup_path. If it succeeds, we go ahead
 // and move the rest.
-bool DeleteTreeWorkItem::Do() {
+bool DeleteTreeWorkItem::DoImpl() {
   // Go through all the key files and see if we can open them exclusively
   // with only the FILE_SHARE_DELETE flag.  Once we know we have all of them,
   // we can delete them.
@@ -58,7 +58,7 @@ bool DeleteTreeWorkItem::Do() {
   for (ptrdiff_t i = 0; !abort && i != num_key_files_; ++i) {
     base::FilePath& key_file = key_paths_[i];
     base::ScopedTempDir& backup = key_backup_paths_[i];
-    if (!ignore_failure_) {
+    if (rollback_enabled()) {
       if (!backup.CreateUniqueTempDirUnderPath(temp_path_)) {
         PLOG(ERROR) << "Could not create temp dir in " << temp_path_.value();
         abort = true;
@@ -107,34 +107,27 @@ bool DeleteTreeWorkItem::Do() {
 
   if (abort) {
     LOG(ERROR) << "Could not exclusively hold all key files.";
-    return ignore_failure_;
+    return false;
   }
 
   // Now that we've taken care of the key files, take care of the rest.
   if (root_path_.empty() || !base::PathExists(root_path_))
     return true;
 
-  if (ignore_failure_) {
-    if (DeleteRoot())
-      return true;
-    // The file cannot be removed, but perhaps it can be moved into
-    // the temporary backup path. Consumers are responsible for making
-    // a best-effort attempt to remove the backup path. SelfCleaningTempDir
-    // is generally used for the backup path, so in the
-    // worst case the file(s) will be removed after the next reboot.
-    MoveRootToBackup();
+  // If rollback is not enabled, try to delete the root without making a backup.
+  // When that fails, fall back to moving the root to the temporary backup path.
+  // Consumers are responsible for making a best-effort attempt to remove the
+  // backup path. SelfCleaningTempDir is generally used for the backup path, so
+  // in the worst case the file(s) will be removed after the next reboot.
+  if (!rollback_enabled() && DeleteRoot())
     return true;
-  }
 
   // Attempt to move the root to the backup.
   return MoveRootToBackup();
 }
 
 // If there are files in backup paths move them back.
-void DeleteTreeWorkItem::Rollback() {
-  if (ignore_failure_)
-    return;
-
+void DeleteTreeWorkItem::RollbackImpl() {
   if (moved_to_backup_) {
     base::FilePath backup = GetBackupPath();
     DCHECK(!backup.empty());