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

chrome/browser/extensions/api/downloads/downloads_api.cc

Index: chrome/browser/extensions/api/downloads/downloads_api.cc
diff --git a/chrome/browser/extensions/api/downloads/downloads_api.cc b/chrome/browser/extensions/api/downloads/downloads_api.cc
index ea28deb0d027ea02f13bf8ead0db165a13c52ad8..859f240d3b0883663a0b903dadc0a82cb04266cd 100644
--- a/chrome/browser/extensions/api/downloads/downloads_api.cc
+++ b/chrome/browser/extensions/api/downloads/downloads_api.cc
@@ -135,7 +135,6 @@ const char* kStateStrings[] = {
   kStateInProgress,
   kStateComplete,
   kStateInterrupted,
-  NULL,
   kStateInterrupted,
 };
 COMPILE_ASSERT(arraysize(kStateStrings) == DownloadItem::MAX_DOWNLOAD_STATE,
@@ -160,7 +159,6 @@ const char* StateString(DownloadItem::DownloadState state) {
   DCHECK(state >= 0);
   DCHECK(state < static_cast<DownloadItem::DownloadState>(
       arraysize(kStateStrings)));
-  DCHECK(state != DownloadItem::REMOVING);
   return kStateStrings[state];
 }
 
@@ -957,25 +955,30 @@ ExtensionDownloadsEventRouter::OnChangedStat::~OnChangedStat() {
     UMA_HISTOGRAM_PERCENTAGE("Download.OnChanged", (fires * 100 / total));
 }
 
-void ExtensionDownloadsEventRouter::OnDownloadUpdated(DownloadItem* item) {
+void ExtensionDownloadsEventRouter::OnDownloadDestructed(DownloadItem* item) {
   if (!profile_)
     return;
   int download_id = item->GetId();
-  if (item->GetState() == DownloadItem::REMOVING) {
-    // The REMOVING state indicates that this item is being erased.
-    // Let's unregister as an observer so that we don't see any more updates
-    // from it, dispatch the onErased event, and remove its json and is
-    // OnChangedStat from our maps.
-    downloads_.erase(download_id);
-    item->RemoveObserver(this);
-    DispatchEvent(extension_event_names::kOnDownloadErased,
-                  base::Value::CreateIntegerValue(download_id));
-    delete item_jsons_[download_id];
-    item_jsons_.erase(download_id);
-    delete on_changed_stats_[download_id];
-    on_changed_stats_.erase(download_id);
+  downloads_.erase(download_id);
+  item->RemoveObserver(this);
+  delete item_jsons_[download_id];
+  item_jsons_.erase(download_id);
+  delete on_changed_stats_[download_id];
+  on_changed_stats_.erase(download_id);
+}
+
+void ExtensionDownloadsEventRouter::OnDownloadRemoved(DownloadItem* item) {
+  if (!profile_)
     return;
-  }
+  int download_id = item->GetId();
+  DispatchEvent(extension_event_names::kOnDownloadErased,
+                base::Value::CreateIntegerValue(download_id));
+}
+
+void ExtensionDownloadsEventRouter::OnDownloadUpdated(DownloadItem* item) {
+  if (!profile_)
+    return;
+  int download_id = item->GetId();
 
   base::DictionaryValue* old_json = item_jsons_[download_id];
   scoped_ptr<base::DictionaryValue> new_json(DownloadItemToJSON(item));
@@ -1024,9 +1027,6 @@ void ExtensionDownloadsEventRouter::OnDownloadUpdated(DownloadItem* item) {
   item_jsons_[download_id]->Swap(new_json.get());
 }
 
-void ExtensionDownloadsEventRouter::OnDownloadOpened(DownloadItem* item) {
-}
-
 void ExtensionDownloadsEventRouter::ModelChanged(DownloadManager* manager) {
   if (!profile_)
     return;
@@ -1077,9 +1077,6 @@ void ExtensionDownloadsEventRouter::ModelChanged(DownloadManager* manager) {
     item_jsons_[*iter] = item.release();
   }
   downloads_.swap(current_map);
-
-  // Dispatching onErased is handled in OnDownloadUpdated when an item
-  // transitions to the REMOVING state.
 }
 
 void ExtensionDownloadsEventRouter::ManagerGoingDown(