Detect removed files and reflect the state in chrome://downloads and the download shelf

chrome/browser/ui/webui/downloads_dom_handler.cc

Index: chrome/browser/ui/webui/downloads_dom_handler.cc
diff --git a/chrome/browser/ui/webui/downloads_dom_handler.cc b/chrome/browser/ui/webui/downloads_dom_handler.cc
index 75209330acf6281ba5b485dfafc317ea080ddd0d..5303a414d9a3d7d31bdb8075ca63c7dd9083c4c3 100644
--- a/chrome/browser/ui/webui/downloads_dom_handler.cc
+++ b/chrome/browser/ui/webui/downloads_dom_handler.cc
@@ -119,23 +119,16 @@ void DownloadsDOMHandler::ModelChanged() {
                                      &download_items_);
   sort(download_items_.begin(), download_items_.end(), DownloadItemSorter());
 
-  // Scan for any in progress downloads and add ourself to them as an observer.
+  // Add oneself to all download items as an observer.
   for (OrderedDownloads::iterator it = download_items_.begin();
        it != download_items_.end(); ++it) {
     if (static_cast<int>(it - download_items_.begin()) > kMaxDownloads)
       break;
-
-    DownloadItem* download = *it;
-    if (download->IsInProgress()) {
-      // We want to know what happens as the download progresses.
-      download->AddObserver(this);
-    } else if (download->safety_state() == DownloadItem::DANGEROUS) {
-      // We need to be notified when the user validates the dangerous download.
-      download->AddObserver(this);
-    }
+    (*it)->AddObserver(this);
   }
 
   SendCurrentDownloads();
+  download_manager_->CheckForHistoryFilesRemoval();
 }
 
 void DownloadsDOMHandler::HandleGetDownloads(const ListValue* args) {