UI changes associated with downloads resumption.

chrome/browser/download/download_shelf_context_menu.cc

Index: chrome/browser/download/download_shelf_context_menu.cc
diff --git a/chrome/browser/download/download_shelf_context_menu.cc b/chrome/browser/download/download_shelf_context_menu.cc
index 43c85ed2a6390c998bfad5f644934000a02593ae..f426c76a63940ea22a1dcfe3e24cadaa30996e28 100644
--- a/chrome/browser/download/download_shelf_context_menu.cc
+++ b/chrome/browser/download/download_shelf_context_menu.cc
@@ -4,12 +4,14 @@
 
 #include "chrome/browser/download/download_shelf_context_menu.h"
 
+#include "base/command_line.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/download/download_crx_util.h"
 #include "chrome/browser/download/download_item_model.h"
 #include "chrome/browser/download/download_prefs.h"
 #include "chrome/browser/safe_browsing/download_protection_service.h"
 #include "chrome/browser/safe_browsing/safe_browsing_service.h"
+#include "chrome/common/chrome_switches.h"
 #include "chrome/common/extensions/extension.h"
 #include "chrome/common/url_constants.h"
 #include "content/public/browser/download_item.h"
@@ -49,6 +51,8 @@ ui::SimpleMenuModel* DownloadShelfContextMenu::GetMenuModel() {
 }
 
 bool DownloadShelfContextMenu::IsCommandIdEnabled(int command_id) const {
+  static bool restart_enabled = CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kEnableDownloadResumption);
   switch (static_cast<ContextMenuCommands>(command_id)) {
     case SHOW_IN_FOLDER:
       return download_item_->CanShowInFolder();
@@ -64,7 +68,7 @@ bool DownloadShelfContextMenu::IsCommandIdEnabled(int command_id) const {
     case CANCEL:
       return download_item_->IsPartialDownload();
     case TOGGLE_PAUSE:
-      return download_item_->IsInProgress();
+      return restart_enabled && download_item_->CanResumeDownload();
     case DISCARD:
     case KEEP:
     case LEARN_MORE_SCANNING:
@@ -173,8 +177,10 @@ string16 DownloadShelfContextMenu::GetLabelForCommandId(int command_id) const {
     case CANCEL:
       return l10n_util::GetStringUTF16(IDS_DOWNLOAD_MENU_CANCEL);
     case TOGGLE_PAUSE: {
-      if (download_item_->IsPaused())
+      if (download_item_->IsPaused() ||
+          download_item_->CanResumeInterrupted()) {
         return l10n_util::GetStringUTF16(IDS_DOWNLOAD_MENU_RESUME_ITEM);
+      }
       return l10n_util::GetStringUTF16(IDS_DOWNLOAD_MENU_PAUSE_ITEM);
     }
     case DISCARD: