Adding WebContent-free Download

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 486 matching lines @@
   return is_temporary_;
 }
 
 bool DownloadItemImpl::CanResume() const {
   if ((GetState() == IN_PROGRESS) && IsPaused())
     return true;
 
   if (state_ != INTERRUPTED_INTERNAL)
     return false;
 
-  // Downloads that don't have a WebContents should still be resumable, but this
-  // isn't currently the case. See ResumeInterruptedDownload().
-  if (!GetWebContents())
+  // We currently only support HTTP(S) requests for download resumption.
+  if (!GetURL().SchemeIsHTTPOrHTTPS())
     return false;
 
   ResumeMode resume_mode = GetResumeMode();
   return IsDownloadResumptionEnabled() &&
       (resume_mode == RESUME_MODE_USER_RESTART ||
        resume_mode == RESUME_MODE_USER_CONTINUE);
 }
 
 bool DownloadItemImpl::IsDone() const {
   switch (state_) {
@@ skipping 1166 matching lines @@
   // this request.
   const base::CommandLine& command_line =
       *base::CommandLine::ForCurrentProcess();
   if (!command_line.HasSwitch(switches::kEnableDownloadResumption))
     return;
 
   // If we're not interrupted, ignore the request; our caller is drunk.
   if (state_ != INTERRUPTED_INTERNAL)
     return;
 
-  // If we can't get a web contents, we can't resume the download.
-  // TODO(rdsmith): Find some alternative web contents to use--this
-  // means we can't restart a download if it's a download imported
-  // from the history.
-  if (!GetWebContents())
-    return;
-
   // Reset the appropriate state if restarting.
   ResumeMode mode = GetResumeMode();
   if (mode == RESUME_MODE_IMMEDIATE_RESTART ||
       mode == RESUME_MODE_USER_RESTART) {
     received_bytes_ = 0;
     hash_state_ = "";
     last_modified_time_ = "";
     etag_ = "";
   }
 
-  scoped_ptr<DownloadUrlParameters> download_params(
-      DownloadUrlParameters::FromWebContents(GetWebContents(),
-                                             GetOriginalUrl()));
+  scoped_ptr<DownloadUrlParameters> download_params;
+  if (GetWebContents()) {
+    download_params = DownloadUrlParameters::FromWebContents(GetWebContents(),
+                                                             GetOriginalUrl());
+  } else if (GetBrowserContext()) {

[asanka, 2015/12/08 16:58:32]

This condition must always be true. DownloadItem (and by implication,
DownloadItemImpl) is indirectly owned by the BrowserContext. I.e.

  - DownloadItemImpl is owned by DownloadManagerImpl
  - DownloadManagerImpl is owned by BrowserContext via UserData.

We would like to make it exist without a BrowserContext, but that's a separate
yak farm than this one :).

[svaldez, 2015/12/08 20:39:26]

GetBrowserContext is null when doing unittesting.

+    download_params = make_scoped_ptr(
+        new DownloadUrlParameters(GetOriginalUrl(), -1, -1, -1,
+                                  GetBrowserContext()->GetResourceContext()));
+  } else {
+    return;
+  }
 
   download_params->set_file_path(GetFullPath());
   download_params->set_offset(GetReceivedBytes());
   download_params->set_hash_state(GetHashState());
   download_params->set_last_modified(GetLastModifiedTime());
   download_params->set_etag(GetETag());
   download_params->set_callback(
       base::Bind(&DownloadItemImpl::OnResumeRequestStarted,
                  weak_ptr_factory_.GetWeakPtr()));
 
@@ skipping 79 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