[Resumption 6/11] Add a RESUMING_INTERNAL state to DownloadItem.

content/browser/download/download_manager_impl.cc

Index: content/browser/download/download_manager_impl.cc
diff --git a/content/browser/download/download_manager_impl.cc b/content/browser/download/download_manager_impl.cc
index 3fa90438b7db8c1af0c9fc03f3f253fddd3c644e..3e970bd16fd5ad344b037c2bd4779a39217c70ed 100644
--- a/content/browser/download/download_manager_impl.cc
+++ b/content/browser/download/download_manager_impl.cc
@@ -247,14 +247,6 @@ DownloadManagerImpl::~DownloadManagerImpl() {
   DCHECK(!shutdown_needed_);
 }
 
-void DownloadManagerImpl::CreateActiveItem(
-    DownloadId id, const DownloadCreateInfo& info) {
-  net::BoundNetLog bound_net_log =
-      net::BoundNetLog::Make(net_log_, net::NetLog::SOURCE_DOWNLOAD);
-  downloads_[id.local()] =
-      item_factory_->CreateActiveItem(this, id, info, bound_net_log);
-}
-
 DownloadId DownloadManagerImpl::GetNextId() {
   DownloadId id;
   if (delegate_)
@@ -377,6 +369,28 @@ DownloadItem* DownloadManagerImpl::StartDownload(
     scoped_ptr<ByteStreamReader> stream) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
+  DownloadId id(info->download_id);
+  bool new_download = !id.IsValid();
+  DownloadItemImpl* download = NULL;
+
+  if (new_download) {
+    id = GetNextId();
+    net::BoundNetLog bound_net_log =
+        net::BoundNetLog::Make(net_log_, net::NetLog::SOURCE_DOWNLOAD);
+    download = item_factory_->CreateActiveItem(this, id, *info, bound_net_log);
+    downloads_[id.local()] = download;
+  } else {
+    // Trying to resume an interrupted download.
+    if (!ContainsKey(downloads_, id.local())) {
+      // If the download is no longer known to the DownloadManager, then it was
+      // removed after it was resumed. Ignore.
+      info->request_handle.CancelRequest();
+      return NULL;
+    }
+    download = downloads_[id.local()];

[Randy Smith (Not in Mondays), 2013/05/13 15:59:26]

I'm tempted to suggest you explicitly look up the iterator, test against end()
to check if the key is there, then dereference to get the download, to avoid the
double lookup.  But I'm good with this code; just wanted to raise the option.

[asanka, 2013/05/13 19:19:01]

Done.

+    DCHECK(download->IsInterrupted());
+  }
+
   base::FilePath default_download_directory;
   if (delegate_) {
     base::FilePath website_save_directory;  // Unused
@@ -385,20 +399,6 @@ DownloadItem* DownloadManagerImpl::StartDownload(
                           &default_download_directory, &skip_dir_check);
   }
 
-  // If we don't have a valid id, that's a signal to generate one.
-  DownloadId id(info->download_id);
-  if (!id.IsValid())
-    id = GetNextId();
-
-  // Create a new download item if this isn't a resumption.
-  bool new_download(!ContainsKey(downloads_, id.local()));
-  if (new_download)
-    CreateActiveItem(id, *info);
-
-  DownloadItemImpl* download(downloads_[id.local()]);
-  DCHECK(download);
-  DCHECK(new_download || download->IsInterrupted());
-
   // Create the download file and start the download.
   scoped_ptr<DownloadFile> download_file(
       file_factory_->CreateFile(