UI changes associated with downloads resumption.

content/browser/download/download_item_impl.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.
 
 // File method ordering: Methods in this file are in the same order as
 // in download_item_impl.h, with the following exception: The public
 // interface Start is placed in chronological order with the other
 // (private) routines that together define a DownloadItem's state
 // transitions as the download progresses.  See "Download progression
 // cascade" later in this file.
@@ skipping 460 matching lines @@
 }
 
 DownloadInterruptReason DownloadItemImpl::GetLastReason() const {
   return last_reason_;
 }
 
 bool DownloadItemImpl::IsPaused() const {
   return is_paused_;
 }
 
+bool DownloadItemImpl::CanResumeInterrupted() const {
+  return GetResumeMode() != RESUME_MODE_INVALID;
+}
+
 bool DownloadItemImpl::IsTemporary() const {
   return is_temporary_;
 }
 
 bool DownloadItemImpl::IsPartialDownload() const {
   DownloadState state = InternalToExternalState(state_);
   return (state == IN_PROGRESS) || (state == INTERRUPTED);
 }
 
 bool DownloadItemImpl::IsInProgress() const {
@@ skipping 188 matching lines @@
 }
 
 bool DownloadItemImpl::CanOpenDownload() {
   // We can open the file or mark it for opening on completion if the download
   // is expected to complete successfully. Exclude temporary downloads, since
   // they aren't owned by the download system.
   return (IsInProgress() || IsComplete()) && !IsTemporary() &&
       !file_externally_removed_;
 }
 
+bool DownloadItemImpl::CanResumeDownload() const {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  // Do not allow interrupted downloads to be resumed until the target name
+  // has been determined, and the user has validated any dangerous items.
+  // TODO(rdsmith) -- Add a state indicating that filename determination has
+  // occurred.
+  if (GetTargetFilePath().empty())
+    return false;
+
+  if (GetSafetyState() == DANGEROUS)
+    return false;
+
+  return IsInProgress() || (GetResumeMode() != RESUME_MODE_INVALID);
+}
+
 bool DownloadItemImpl::ShouldOpenFileBasedOnExtension() {
   return delegate_->ShouldOpenFileBasedOnExtension(GetUserVerifiedFilePath());
 }
 
 bool DownloadItemImpl::GetOpenWhenComplete() const {
   return open_when_complete_;
 }
 
 bool DownloadItemImpl::GetAutoOpened() {
   return auto_opened_;
@@ skipping 964 matching lines @@
     case RESUME_MODE_USER_CONTINUE:
       return "USER_CONTINUE";
     case RESUME_MODE_USER_RESTART:
       return "USER_RESTART";
   }
   NOTREACHED() << "Unknown resume mode " << mode;
   return "unknown";
 }
 
 }  // namespace content