Reland DownloadItem::Observer::OnDownloadDestroyed() replaces DownloadItem::REMOVING

content/browser/download/download_manager_impl.cc

Index: content/browser/download/download_manager_impl.cc
diff --git a/content/browser/download/download_manager_impl.cc b/content/browser/download/download_manager_impl.cc
index ce33228f748c7f0ac84d63d8bb56d7fb38c1e1bc..094fbdf47b0c6d1ea992525fc560f587af36ea0f 100644
--- a/content/browser/download/download_manager_impl.cc
+++ b/content/browser/download/download_manager_impl.cc
@@ -322,13 +322,9 @@ void DownloadManagerImpl::Shutdown() {
   // and all in progress downloads have been cancelled.  We can now delete
   // anything left.
 
-  // Copy downloads_ to separate container so as not to set off checks
-  // in DownloadItem destruction.
-  DownloadMap downloads_to_delete;
-  downloads_to_delete.swap(downloads_);
-
   active_downloads_.clear();
-  STLDeleteValues(&downloads_to_delete);
+  STLDeleteValues(&downloads_);
+  downloads_.clear();
 
   // We'll have nothing more to report to the observers after this point.
   observers_.Clear();
@@ -618,13 +614,6 @@ void DownloadManagerImpl::OnResponseCompleted(int32 download_id,
 
 void DownloadManagerImpl::AssertStateConsistent(
     DownloadItemImpl* download) const {
-  if (download->GetState() == DownloadItem::REMOVING) {
-    DCHECK(!ContainsKey(downloads_, download->GetId()));
-    DCHECK(!ContainsKey(active_downloads_, download->GetId()));
-    return;
-  }
-
-  // Should be in downloads_ if we're not REMOVING.
   CHECK(ContainsKey(downloads_, download->GetId()));
 
   int64 state = download->GetState();
@@ -783,20 +772,16 @@ int DownloadManagerImpl::RemoveDownloadItems(
 
   // Delete from internal maps.
   for (DownloadItemImplVector::const_iterator it = pending_deletes.begin();
-      it != pending_deletes.end();
-      ++it) {
+       it != pending_deletes.end();
+       ++it) {
     DownloadItemImpl* download = *it;
     DCHECK(download);
-    downloads_.erase(download->GetId());
+    int32 download_id = download->GetId();
+    delete download;
+    downloads_.erase(download_id);
   }
-
-  // Tell observers to refresh their views.
   NotifyModelChanged();
-
-  // Delete the download items themselves.
-  const int num_deleted = static_cast<int>(pending_deletes.size());
-  STLDeleteContainerPointers(pending_deletes.begin(), pending_deletes.end());
-  return num_deleted;
+  return static_cast<int>(pending_deletes.size());
 }
 
 void DownloadManagerImpl::DownloadRemoved(DownloadItemImpl* download) {
@@ -823,8 +808,6 @@ int DownloadManagerImpl::RemoveDownloadsBetween(base::Time remove_begin,
   if (delegate_)
     delegate_->RemoveItemsFromPersistentStoreBetween(remove_begin, remove_end);
 
-  // All downloads visible to the user will be in the history,
-  // so scan that map.
   DownloadItemImplVector pending_deletes;
   for (DownloadMap::const_iterator it = downloads_.begin();
       it != downloads_.end();
@@ -835,6 +818,7 @@ int DownloadManagerImpl::RemoveDownloadsBetween(base::Time remove_begin,
         (remove_end.is_null() || download->GetStartTime() < remove_end) &&
         (download->IsComplete() || download->IsCancelled())) {
       AssertStateConsistent(download);
+      download->NotifyRemoved();
       pending_deletes.push_back(download);
     }
   }