Preliminary work on resuming downloads whose connections have expired.

chrome/browser/download/download_item.cc

Index: chrome/browser/download/download_item.cc
diff --git a/chrome/browser/download/download_item.cc b/chrome/browser/download/download_item.cc
index 787b8ad0a7165468337af6138e6c3de77339601d..4275e08548ab2adff611997813de962476eab1e8 100644
--- a/chrome/browser/download/download_item.cc
+++ b/chrome/browser/download/download_item.cc
@@ -48,6 +48,7 @@ DownloadItem::DownloadItem(DownloadManager* download_manager,
       original_mime_type_(info.original_mime_type),
       total_bytes_(info.total_bytes),
       received_bytes_(info.received_bytes),
+      last_os_error_(0),
       start_tick_(base::TimeTicks()),
       state_(static_cast<DownloadState>(info.state)),
       start_time_(info.start_time),
@@ -85,6 +86,7 @@ DownloadItem::DownloadItem(DownloadManager* download_manager,
       original_mime_type_(info.original_mime_type),
       total_bytes_(info.total_bytes),
       received_bytes_(0),
+      last_os_error_(0),
       start_tick_(base::TimeTicks::Now()),
       state_(IN_PROGRESS),
       start_time_(info.start_time),
@@ -101,7 +103,8 @@ DownloadItem::DownloadItem(DownloadManager* download_manager,
       is_otr_(is_otr),
       is_extension_install_(info.is_extension_install),
       name_finalized_(false),
-      is_temporary_(!info.save_info.file_path.empty()),
+      is_temporary_(!info.save_info.file_path.empty() &&
+                    !info.is_partial_download),
       need_final_rename_(false),
       opened_(false) {
   Init(true /* start progress timer */);
@@ -121,6 +124,7 @@ DownloadItem::DownloadItem(DownloadManager* download_manager,
       original_mime_type_(std::string()),
       total_bytes_(0),
       received_bytes_(0),
+      last_os_error_(0),
       start_tick_(base::TimeTicks::Now()),
       state_(IN_PROGRESS),
       start_time_(base::Time::Now()),
@@ -186,9 +190,9 @@ void DownloadItem::OpenFilesBasedOnExtension(bool open) {
 }
 
 void DownloadItem::OpenDownload() {
-  if (state() == DownloadItem::IN_PROGRESS) {
+  if (state() == IN_PROGRESS) {
     open_when_complete_ = !open_when_complete_;
-  } else if (state() == DownloadItem::COMPLETE) {
+  } else if (state() == COMPLETE) {
     opened_ = true;
     FOR_EACH_OBSERVER(Observer, observers_, OnDownloadOpened(this));
     if (is_extension_install()) {
@@ -250,14 +254,18 @@ void DownloadItem::Update(int64 bytes_so_far) {
     NOTREACHED();
     return;
   }
+  // May get called once in the INTERRUPTED state.
+  if (state_ == INTERRUPTED)
+    return;
   UpdateSize(bytes_so_far);
   UpdateObservers();
 }
 
 // Triggered by a user action.
 void DownloadItem::Cancel(bool update_history) {
-  if (state_ != IN_PROGRESS) {
-    // Small downloads might be complete before this method has a chance to run.
+  if (!IsPartialDownload()) {
+    // Small downloads might be complete or interrupted before this method has
+    // a chance to run.
     return;
   }
   state_ = CANCELLED;
@@ -303,6 +311,23 @@ void DownloadItem::Finished() {
     NotifyObserversDownloadFileCompleted();
 }
 
+void DownloadItem::Interrupted(int64 size, int os_error) {
+  if (state_ != IN_PROGRESS)
+    return;
+  state_ = INTERRUPTED;
+  last_os_error_ = os_error;
+  UpdateSize(size);
+  StopProgressTimer();
+}
+
+void DownloadItem::Resumed(int new_request_id) {
+  if (state_ != INTERRUPTED)
+    return;
+  state_ = IN_PROGRESS;
+  request_id_ = new_request_id;
+  StartProgressTimer();
+}
+
 void DownloadItem::Remove(bool delete_on_disk) {
   Cancel(true);
   state_ = REMOVING;
@@ -348,9 +373,13 @@ void DownloadItem::Rename(const FilePath& full_path) {
 }
 
 void DownloadItem::TogglePause() {
-  DCHECK(state_ == IN_PROGRESS);
-  download_manager_->PauseDownload(id_, !is_paused_);
-  is_paused_ = !is_paused_;
+  DCHECK(IsPartialDownload());
+  if (state_ == IN_PROGRESS) {
+    download_manager_->PauseDownload(id_, !is_paused_);
+    is_paused_ = !is_paused_;
+  } else {
+    download_manager_->RestartDownload(id_);
+  }
   UpdateObservers();
 }
 
@@ -393,6 +422,14 @@ bool DownloadItem::MatchesQuery(const string16& query) const {
   return false;
 }
 
+bool DownloadItem::IsPartialDownload() const {
+  return (state_ == IN_PROGRESS) || (state_ == INTERRUPTED);
+}
+
+bool DownloadItem::IsInterruptedDownload() const {
+  return (state_ == INTERRUPTED);
+}
+
 FilePath DownloadItem::GetFileName() const {
   if (safety_state_ == DownloadItem::SAFE)
     return file_name_;