MD Downloads: limit the amount of downloads we send

chrome/browser/ui/webui/md_downloads/md_downloads_dom_handler.cc

 // Copyright (c) 2012 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/ui/webui/md_downloads/md_downloads_dom_handler.h"
 
 #include <algorithm>
 #include <functional>
 
 #include "base/basictypes.h"
@@ skipping 118 matching lines @@
       base::Bind(&MdDownloadsDOMHandler::HandleClearAll,
                  weak_ptr_factory_.GetWeakPtr()));
   web_ui()->RegisterMessageCallback("openDownloadsFolder",
       base::Bind(&MdDownloadsDOMHandler::HandleOpenDownloadsFolder,
                  weak_ptr_factory_.GetWeakPtr()));
 }
 
 void MdDownloadsDOMHandler::RenderViewReused(
     content::RenderViewHost* render_view_host) {
   list_tracker_.Stop();
+  list_tracker_.Reset();
 }
 
 void MdDownloadsDOMHandler::HandleGetDownloads(const base::ListValue* args) {
   CountDownloadsDOMEvents(DOWNLOADS_DOM_EVENT_GET_DOWNLOADS);
 
   bool terms_changed = list_tracker_.SetSearchTerms(*args);
   if (terms_changed)
-    list_tracker_.CallClearAll();
+    list_tracker_.Reset();
 
-  list_tracker_.Start();
+  list_tracker_.StartAndSendChunk();
 }
 
 void MdDownloadsDOMHandler::HandleOpenFile(const base::ListValue* args) {
   CountDownloadsDOMEvents(DOWNLOADS_DOM_EVENT_OPEN_FILE);
   content::DownloadItem* file = GetDownloadByValue(args);
   if (file)
     file->OpenDownload();
 }
 
 void MdDownloadsDOMHandler::HandleDrag(const base::ListValue* args) {
@@ skipping 72 matching lines @@
 }
 
 void MdDownloadsDOMHandler::HandleUndo(const base::ListValue* args) {
   // TODO(dbeam): handle more than removed downloads someday?
   if (removals_.empty())
     return;
 
   const IdSet last_removed_ids = removals_.back();
   removals_.pop_back();
 
+  const bool undoing_clear_all = last_removed_ids.size() > 1;
+  if (undoing_clear_all) {
+    list_tracker_.Reset();
+    list_tracker_.Stop();
+  }
+
   for (auto id : last_removed_ids) {
     content::DownloadItem* download = GetDownloadById(id);
     if (!download)
       continue;
 
     DownloadItemModel model(download);
     model.SetShouldShowInShelf(true);
     model.SetIsBeingRevived(true);
 
     download->UpdateObservers();
 
     model.SetIsBeingRevived(false);
   }
+
+  if (undoing_clear_all)
+    list_tracker_.StartAndSendChunk();
 }
 
 void MdDownloadsDOMHandler::HandleCancel(const base::ListValue* args) {
   CountDownloadsDOMEvents(DOWNLOADS_DOM_EVENT_CANCEL);
   content::DownloadItem* file = GetDownloadByValue(args);
   if (file)
     file->Cancel(true);
 }
 
 void MdDownloadsDOMHandler::HandleClearAll(const base::ListValue* args) {
   if (!IsDeletingHistoryAllowed()) {
     // This should only be reached during tests.
     return;
   }
 
   CountDownloadsDOMEvents(DOWNLOADS_DOM_EVENT_CLEAR_ALL);
 
-  list_tracker_.CallClearAll();
+  list_tracker_.Reset();
   list_tracker_.Stop();
 
   DownloadVector downloads;
   if (GetMainNotifierManager())
     GetMainNotifierManager()->GetAllDownloads(&downloads);
   if (GetOriginalNotifierManager())
     GetOriginalNotifierManager()->GetAllDownloads(&downloads);
   RemoveDownloads(downloads);
 
-  list_tracker_.Start();
+  list_tracker_.StartAndSendChunk();
 }
 
 void MdDownloadsDOMHandler::RemoveDownloads(const DownloadVector& to_remove) {
   IdSet ids;
 
   for (auto* download : to_remove) {
     DownloadItemModel item_model(download);
     if (!item_model.ShouldShowInShelf() ||
         download->GetState() == content::DownloadItem::IN_PROGRESS) {
       continue;
@@ skipping 101 matching lines @@
   if (GetMainNotifierManager())
     item = GetMainNotifierManager()->GetDownload(id);
   if (!item && GetOriginalNotifierManager())
     item = GetOriginalNotifierManager()->GetDownload(id);
   return item;
 }
 
 content::WebContents* MdDownloadsDOMHandler::GetWebUIWebContents() {
   return web_ui()->GetWebContents();
 }