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

chrome/browser/download/download_manager.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/download/download_manager.h"
 
 #include "base/callback.h"
 #include "base/file_util.h"
 #include "base/i18n/case_conversion.h"
 #include "base/logging.h"
@@ skipping 247 matching lines @@
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   // Create a client to verify download URL with safebrowsing.
   // It deletes itself after the callback.
   scoped_refptr<DownloadSBClient> sb_client = new DownloadSBClient(
       info->download_id, info->url_chain, info->referrer_url);
   sb_client->CheckDownloadUrl(
       info, NewCallback(this, &DownloadManager::CheckDownloadUrlDone));
 }
 
+void DownloadManager::CheckForFilesRemoval() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  for (DownloadMap::iterator it = history_downloads_.begin();
+       it != history_downloads_.end(); ++it) {
+    DownloadItem* download_item = it->second;
+    if (download_item->IsComplete() &&
+        !download_item->file_externally_removed()) {
+        BrowserThread::PostTask(
+            BrowserThread::FILE, FROM_HERE,
+            NewRunnableMethod(this,
+                &DownloadManager::CheckForFileRemovalOnFileThread,
+                it->first, download_item->GetTargetFilePath()));
+    }
+  }
+}
+
+void DownloadManager::CheckForFileRemovalOnFileThread(
+    int64 db_handle, const FilePath& path) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  if (!file_util::PathExists(path)) {
+    BrowserThread::PostTask(
+        BrowserThread::UI, FROM_HERE,
+        NewRunnableMethod(this,
+                          &DownloadManager::OnFileRemovalDetected,
+                          db_handle));
+  }
+}
+
+void DownloadManager::OnFileRemovalDetected(int64 db_handle) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DownloadMap::iterator it = history_downloads_.find(db_handle);
+  if (it != history_downloads_.end()) {
+    DownloadItem* download_item = it->second;
+    download_item->OnDownloadedFileRemoved();
+  }
+}
+
 void DownloadManager::CheckDownloadUrlDone(DownloadCreateInfo* info,
                                            bool is_dangerous_url) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DCHECK(info);
 
   info->is_dangerous_url = is_dangerous_url;
 
   // Check whether this download is for an extension install or not.
   // Allow extensions to be explicitly saved.
   if (!info->prompt_user_for_save_location) {
@@ skipping 897 matching lines @@
     observed_download_manager_->RemoveObserver(this);
 }
 
 void DownloadManager::OtherDownloadManagerObserver::ModelChanged() {
   observing_download_manager_->NotifyModelChanged();
 }
 
 void DownloadManager::OtherDownloadManagerObserver::ManagerGoingDown() {
   observed_download_manager_ = NULL;
 }