Update AttachmentServiceImpl to retry attachment uploads.

sync/internal_api/attachments/attachment_downloader_impl.cc

 // Copyright 2014 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.
 
 #include "sync/internal_api/public/attachments/attachment_downloader_impl.h"
 
 #include "base/bind.h"
 #include "base/message_loop/message_loop.h"
 #include "net/base/load_flags.h"
 #include "net/http/http_status_code.h"
@@ skipping 97 matching lines @@
   DCHECK(request == access_token_request_.get());
   access_token_request_.reset();
   StateList::const_iterator iter;
   // Without access token all downloads fail.
   for (iter = requests_waiting_for_access_token_.begin();
        iter != requests_waiting_for_access_token_.end();
        ++iter) {
     DownloadState* download_state = *iter;
     scoped_refptr<base::RefCountedString> null_attachment_data;
     ReportResult(
-        *download_state, DOWNLOAD_UNSPECIFIED_ERROR, null_attachment_data);
+        *download_state, DOWNLOAD_TRANSIENT_ERROR, null_attachment_data);
     DCHECK(state_map_.find(download_state->attachment_url) != state_map_.end());
     state_map_.erase(download_state->attachment_url);
   }
   requests_waiting_for_access_token_.clear();
 }
 
 void AttachmentDownloaderImpl::OnURLFetchComplete(
     const net::URLFetcher* source) {
   DCHECK(CalledOnValidThread());
 
   // Find DownloadState by url.
   AttachmentUrl url = source->GetOriginalURL().spec();
   StateMap::iterator iter = state_map_.find(url);
   DCHECK(iter != state_map_.end());
   const DownloadState& download_state = *iter->second;
   DCHECK(source == download_state.url_fetcher.get());
 
-  DownloadResult result = DOWNLOAD_UNSPECIFIED_ERROR;
+  DownloadResult result = DOWNLOAD_TRANSIENT_ERROR;
   scoped_refptr<base::RefCountedString> attachment_data;
 
-  if (source->GetResponseCode() == net::HTTP_OK) {
+  const int response_code = source->GetResponseCode();
+  if (response_code == net::HTTP_OK) {
     result = DOWNLOAD_SUCCESS;
     std::string data_as_string;
     source->GetResponseAsString(&data_as_string);
     attachment_data = base::RefCountedString::TakeString(&data_as_string);
-  } else if (source->GetResponseCode() == net::HTTP_UNAUTHORIZED) {
+  } else if (response_code == net::HTTP_UNAUTHORIZED) {
+    // Server tells us we've got a bad token so invalidate it.
     OAuth2TokenServiceRequest::InvalidateToken(token_service_provider_.get(),
                                                account_id_,
                                                oauth2_scopes_,
                                                download_state.access_token);
-    // TODO(pavely): crbug/380437. This is transient error. Request new access
-    // token for this DownloadState. The only trick is to do it with exponential
-    // backoff.
+    // Fail the request, but indicate that it may be successful if retried.
+    result = DOWNLOAD_TRANSIENT_ERROR;
+  } else if (response_code == net::HTTP_FORBIDDEN) {
+    // User is not allowed to use attachments.  Retrying won't help.
+    result = DOWNLOAD_UNSPECIFIED_ERROR;
+  } else if (response_code == net::URLFetcher::RESPONSE_CODE_INVALID) {
+    result = DOWNLOAD_TRANSIENT_ERROR;
   }
   ReportResult(download_state, result, attachment_data);
   state_map_.erase(iter);
 }
 
 scoped_ptr<net::URLFetcher> AttachmentDownloaderImpl::CreateFetcher(
     const AttachmentUrl& url,
     const std::string& access_token) {
   scoped_ptr<net::URLFetcher> url_fetcher(
       net::URLFetcher::Create(GURL(url), net::URLFetcher::GET, this));
+  url_fetcher->SetAutomaticallyRetryOn5xx(false);
   const std::string auth_header("Authorization: Bearer " + access_token);
   url_fetcher->AddExtraRequestHeader(auth_header);
   url_fetcher->SetRequestContext(url_request_context_getter_.get());
   url_fetcher->SetLoadFlags(net::LOAD_DO_NOT_SAVE_COOKIES |
                             net::LOAD_DO_NOT_SEND_COOKIES |
                             net::LOAD_DISABLE_CACHE);
   // TODO(maniscalco): Set an appropriate headers (User-Agent, what else?) on
   // the request (bug 371521).
   return url_fetcher.Pass();
 }
@@ skipping 21 matching lines @@
       attachment.reset(new Attachment(Attachment::CreateWithId(
           download_state.attachment_id, attachment_data)));
     }
 
     base::MessageLoop::current()->PostTask(
         FROM_HERE, base::Bind(*iter, result, base::Passed(&attachment)));
   }
 }
 
 }  // namespace syncer