Reland "Fix various issues in RedirectToFileResourceHandler."

It got reverted due to ASan issues. Fix child_id registration in
ResourceDispatcherHostTests so that they happen on ForwardingFilter creation,
rather than ad-hoc on a per-request basis.

Original description:

> - Handle errors in creating temporary files.
> - Cancel on write failure instead of resuming. This used to work, but got
>   lost in some refactoring in r142108.
> - Fix the OnResponseCompleted resume logic to account for partial writes.
> - Don't lose write errors which occur after OnResponseCompleted is received.
> - WeakPtrFactory goes after other members.
> - OnWillStart was never forwarded to downstream handlers.
> - Make sure the file is closed before deleting it.
>
> Also add a lot of machinery so we can better unit test this stack.

Original Review URL: https://codereview.chromium.org/82273002

BUG=316634,347663
TEST=ResourceDispatcherHostTest.DownloadToFile
     ResourceDispatcherHostTest.RegisterDownloadedTempFile
     ResourceLoaderRedirectToFileTest.*
     TemporaryFileStreamTest.Basic

Review URL: https://codereview.chromium.org/199453002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@257147 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 12 insertions, 0 deletions

diff --git a/content/browser/loader/sync_resource_handler.cc b/content/browser/loader/sync_resource_handler.cc
index 865b29e..e39ae1c 100644
--- a/content/browser/loader/sync_resource_handler.cc
+++ b/content/browser/loader/sync_resource_handler.cc
@@ -86,6 +86,18 @@ bool SyncResourceHandler::OnResponseStarted(
 
   DevToolsNetLogObserver::PopulateResponseInfo(request(), response);
 
+  // If the parent handler downloaded the resource to a file, grant the child
+  // read permissions on it. Note: there is similar logic in
+  // AsyncResourceHandler.
+  //
+  // TODO(davidben): Can we remove support for download_file in sync requests
+  // altogether? I don't think Blink ever makes such requests.
+  if (!response->head.download_file_path.empty()) {
+    rdh_->RegisterDownloadedTempFile(
+        info->GetChildID(), info->GetRequestID(),
+        response->head.download_file_path);
+  }
+
   // We don't care about copying the status here.
   result_.headers = response->head.headers;
   result_.mime_type = response->head.mime_type;