Preliminary work on resuming downloads whose connections have expired.

chrome/browser/download/download_shelf.cc

Index: chrome/browser/download/download_shelf.cc
diff --git a/chrome/browser/download/download_shelf.cc b/chrome/browser/download/download_shelf.cc
index dc69d02c4f029000180e3a49fea680e723f76f25..5adc587faeb2e07225e9bf21d443d0aeb57d543f 100644
--- a/chrome/browser/download/download_shelf.cc
+++ b/chrome/browser/download/download_shelf.cc
@@ -5,6 +5,7 @@
 #include "chrome/browser/download/download_shelf.h"
 
 #include "app/l10n_util.h"
+#include "base/command_line.h"
 #include "base/file_util.h"
 #include "chrome/browser/browser.h"
 #include "chrome/browser/dom_ui/downloads_ui.h"
@@ -14,6 +15,7 @@
 #include "chrome/browser/download/download_util.h"
 #include "chrome/browser/metrics/user_metrics.h"
 #include "chrome/common/url_constants.h"
+#include "chrome/common/chrome_switches.h"
 #include "grit/generated_resources.h"
 
 // DownloadShelfContextMenu ----------------------------------------------------
@@ -50,7 +52,7 @@ string16 DownloadShelfContextMenu::GetLabelForCommandId(int command_id) const {
     case CANCEL:
       return l10n_util::GetStringUTF16(IDS_DOWNLOAD_MENU_CANCEL);
     case TOGGLE_PAUSE: {
-      if (download_->is_paused())
+      if (download_->is_paused() || download_->IsInterruptedDownload())
         return l10n_util::GetStringUTF16(IDS_DOWNLOAD_MENU_RESUME_ITEM);
       else
         return l10n_util::GetStringUTF16(IDS_DOWNLOAD_MENU_PAUSE_ITEM);
@@ -62,6 +64,8 @@ string16 DownloadShelfContextMenu::GetLabelForCommandId(int command_id) const {
 }
 
 bool DownloadShelfContextMenu::IsCommandIdEnabled(int command_id) const {
+  static bool can_restart = CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kEnableDownloadRestarts);
   switch (command_id) {
     case SHOW_IN_FOLDER:
     case OPEN_WHEN_COMPLETE:
@@ -69,9 +73,11 @@ bool DownloadShelfContextMenu::IsCommandIdEnabled(int command_id) const {
     case ALWAYS_OPEN_TYPE:
       return download_->CanOpenDownload();
     case CANCEL:
-      return download_->state() == DownloadItem::IN_PROGRESS;
+      return download_->IsPartialDownload();
     case TOGGLE_PAUSE:
-      return download_->state() == DownloadItem::IN_PROGRESS;
+      return ((download_->state() == DownloadItem::IN_PROGRESS) ||
+              (can_restart &&
+                   (download_->IsInterruptedDownload())));
     default:
       return command_id > 0 && command_id < MENU_LAST;
   }
@@ -97,7 +103,7 @@ void DownloadShelfContextMenu::ExecuteCommand(int command_id) {
       // It is possible for the download to complete before the user clicks the
       // menu item, recheck if the download is in progress state before toggling
       // pause.
-      if (download_->state() == DownloadItem::IN_PROGRESS)
+      if (download_->IsPartialDownload())
         download_->TogglePause();
       break;
     default: