downloads: break downloads.js into more classes/files.

chrome/browser/download/download_item_model.cc

Index: chrome/browser/download/download_item_model.cc
diff --git a/chrome/browser/download/download_item_model.cc b/chrome/browser/download/download_item_model.cc
index f1ef10f5bcfbf2dc4d54c27888feb39e1a25f73e..f29d7e937c5156d71c9d092845afe9a20ff1a48e 100644
--- a/chrome/browser/download/download_item_model.cc
+++ b/chrome/browser/download/download_item_model.cc
@@ -63,6 +63,9 @@ class DownloadItemModelData : public base::SupportsUserData::Data {
   // come up with a verdict.
   bool is_dangerous_file_based_on_type_;
 
+  // Whether the download is currently being revived.
+  bool is_being_revived_;
+
  private:
   DownloadItemModelData();
   ~DownloadItemModelData() override {}
@@ -95,7 +98,8 @@ DownloadItemModelData::DownloadItemModelData()
     : should_show_in_shelf_(true),
       was_ui_notified_(false),
       should_prefer_opening_in_browser_(false),
-      is_dangerous_file_based_on_type_(false) {
+      is_dangerous_file_based_on_type_(false),
+      is_being_revived_(false) {
 }
 
 base::string16 InterruptReasonStatusMessage(int reason) {
@@ -610,6 +614,16 @@ void DownloadItemModel::SetIsDangerousFileBasedOnType(bool dangerous) {
   data->is_dangerous_file_based_on_type_ = dangerous;
 }
 
+bool DownloadItemModel::IsBeingRevived() const {
+  const DownloadItemModelData* data = DownloadItemModelData::Get(download_);
+  return data && data->is_being_revived_;
+}
+
+void DownloadItemModel::SetIsBeingRevived(bool is_being_revived) {
+  DownloadItemModelData* data = DownloadItemModelData::GetOrCreate(download_);
+  data->is_being_revived_ = is_being_revived;
+}
+
 base::string16 DownloadItemModel::GetProgressSizesString() const {
   base::string16 size_ratio;
   int64 size = GetCompletedBytes();