Revert 149794 - DownloadItem::Observer::OnDownloadDestroyed() replaces DownloadItem::REMOVING

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

Index: chrome/browser/extensions/api/downloads/downloads_api.cc
===================================================================
--- chrome/browser/extensions/api/downloads/downloads_api.cc	(revision 150095)
+++ chrome/browser/extensions/api/downloads/downloads_api.cc	(working copy)
@@ -139,6 +139,7 @@
   kStateInProgress,
   kStateComplete,
   kStateInterrupted,
+  NULL,
   kStateInterrupted,
 };
 COMPILE_ASSERT(arraysize(kStateStrings) == DownloadItem::MAX_DOWNLOAD_STATE,
@@ -163,6 +164,7 @@
   DCHECK(state >= 0);
   DCHECK(state < static_cast<DownloadItem::DownloadState>(
       arraysize(kStateStrings)));
+  DCHECK(state != DownloadItem::REMOVING);
   return kStateStrings[state];
 }
 
@@ -818,32 +820,25 @@
     UMA_HISTOGRAM_PERCENTAGE("Download.OnChanged", (fires * 100 / total));
 }
 
-void ExtensionDownloadsEventRouter::OnDownloadDestroyed(DownloadItem* item) {
+void ExtensionDownloadsEventRouter::OnDownloadUpdated(DownloadItem* item) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   int download_id = item->GetId();
-  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) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  if (!profile_)
+  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(extensions::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);
     return;
-  int download_id = item->GetId();
-  DispatchEvent(extensions::event_names::kOnDownloadErased,
-                base::Value::CreateIntegerValue(download_id));
-}
+  }
 
-void ExtensionDownloadsEventRouter::OnDownloadUpdated(DownloadItem* item) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  if (!profile_)
-    return;
-  int download_id = item->GetId();
-
   base::DictionaryValue* old_json = item_jsons_[download_id];
   scoped_ptr<base::DictionaryValue> new_json(DownloadItemToJSON(item));
   scoped_ptr<base::DictionaryValue> delta(new base::DictionaryValue());
@@ -891,6 +886,10 @@
   item_jsons_[download_id]->Swap(new_json.get());
 }
 
+void ExtensionDownloadsEventRouter::OnDownloadOpened(DownloadItem* item) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+}
+
 void ExtensionDownloadsEventRouter::OnDownloadCreated(
     DownloadManager* manager, DownloadItem* download_item) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
@@ -914,7 +913,6 @@
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   manager_->RemoveObserver(this);
   manager_ = NULL;
-  profile_ = NULL;
 }
 
 void ExtensionDownloadsEventRouter::DispatchEvent(