[Resumption 11/12] Support resuming interrupted downloads from the downloads shelf.

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 f7555ea2ad481ee6482ce73038ba725ecd82f9e0..d376da843a251dc8fd1dd7ffac200de1daf6a170 100644
--- a/chrome/browser/download/download_shelf_context_menu.cc
+++ b/chrome/browser/download/download_shelf_context_menu.cc
@@ -4,6 +4,7 @@
 
 #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"
@@ -15,12 +16,23 @@
 #include "content/public/browser/download_item.h"
 #include "content/public/browser/download_manager.h"
 #include "content/public/browser/page_navigator.h"
+#include "content/public/common/content_switches.h"
 #include "grit/generated_resources.h"
 #include "ui/base/l10n/l10n_util.h"
 
 using content::DownloadItem;
 using extensions::Extension;
 
+namespace {
+
+// Returns true if downloads resumption is enabled.
+bool IsDownloadResumptionEnabled() {
+  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+  return command_line.HasSwitch(switches::kEnableDownloadResumption);
+}
+
+} // namespace
+
 DownloadShelfContextMenu::~DownloadShelfContextMenu() {
   DetachFromDownloadItem();
 }
@@ -76,6 +88,8 @@ bool DownloadShelfContextMenu::IsCommandIdEnabled(int command_id) const {
       return download_item_->IsPartialDownload();
     case TOGGLE_PAUSE:
       return download_item_->GetState() == DownloadItem::IN_PROGRESS;
+    case RESUME_INTERRUPTED:
+      return download_item_->IsInterrupted() && download_item_->CanResume();

[Randy Smith (Not in Mondays), 2013/06/05 20:12:55]

Actually, an extra high-level question: Why not just expand the TOGGLE_PAUSE
item to do the resume interrupted functionality?  (Not blocking landing; just
curious as to why you made this design choice.)

[asanka, 2013/06/05 20:29:17]

Good question. I did it that way the first time around, and TOGGLE_PAUSE seemed
like the wrong action to trigger a resumption for an interrupted download. Back
when this CL was started, resumption was via
DownloadItem::ResumeInterruptedDownload().

I'll change it back to TOGGLE_PAUSE with appropriate documentation.

     case DISCARD:
     case KEEP:
     case LEARN_MORE_SCANNING:
@@ -136,6 +150,9 @@ void DownloadShelfContextMenu::ExecuteCommand(int command_id, int event_flags) {
           download_item_->Pause();
       }
       break;
+    case RESUME_INTERRUPTED:
+      download_item_->Resume();
+      break;
     case DISCARD:
       download_item_->Remove();
       break;
@@ -194,6 +211,8 @@ string16 DownloadShelfContextMenu::GetLabelForCommandId(int command_id) const {
       if (download_item_ && download_item_->IsPaused())
         return l10n_util::GetStringUTF16(IDS_DOWNLOAD_MENU_RESUME_ITEM);
       return l10n_util::GetStringUTF16(IDS_DOWNLOAD_MENU_PAUSE_ITEM);
+    case RESUME_INTERRUPTED:
+      return l10n_util::GetStringUTF16(IDS_DOWNLOAD_MENU_RESUME_ITEM);
     case DISCARD:
       return l10n_util::GetStringUTF16(IDS_DOWNLOAD_MENU_DISCARD);
     case KEEP:
@@ -264,22 +283,36 @@ ui::SimpleMenuModel* DownloadShelfContextMenu::GetFinishedMenuModel() {
 }
 
 ui::SimpleMenuModel* DownloadShelfContextMenu::GetInterruptedMenuModel() {
-#if defined(OS_WIN)
-  // The Help Center article is currently Windows specific.
-  // TODO(asanka): Enable this for other platforms when the article is expanded
-  // for other platforms.
+#if !defined(OS_WIN)
+  // If resumption isn't enabled and we aren't on Windows, then none of the
+  // options here are applicable.
+  if (!IsDownloadResumptionEnabled())
+    return GetInProgressMenuModel();
+#endif
+
   if (interrupted_download_menu_model_)
     return interrupted_download_menu_model_.get();
 
   interrupted_download_menu_model_.reset(new ui::SimpleMenuModel(this));
 
+  if (IsDownloadResumptionEnabled()) {
+    interrupted_download_menu_model_->AddItemWithStringId(
+        RESUME_INTERRUPTED, IDS_DOWNLOAD_MENU_RESUME_ITEM);
+  }
+#if defined(OS_WIN)
+  // The Help Center article is currently Windows specific.
+  // TODO(asanka): Enable this for other platforms when the article is expanded
+  // for other platforms.
   interrupted_download_menu_model_->AddItemWithStringId(
       LEARN_MORE_INTERRUPTED, IDS_DOWNLOAD_MENU_LEARN_MORE_INTERRUPTED);
+#endif
+  if (IsDownloadResumptionEnabled()) {
+    interrupted_download_menu_model_->AddSeparator(ui::NORMAL_SEPARATOR);
+    interrupted_download_menu_model_->AddItemWithStringId(
+        CANCEL, IDS_DOWNLOAD_MENU_CANCEL);
+  }
 
   return interrupted_download_menu_model_.get();
-#else
-  return GetInProgressMenuModel();
-#endif
 }
 
 ui::SimpleMenuModel* DownloadShelfContextMenu::GetMaliciousMenuModel() {