Shift URLRequest::Read API contract used by fetcher to ResourceLoader's.

net/url_request/sdch_dictionary_fetcher.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 "net/url_request/sdch_dictionary_fetcher.h"
 
 #include <stdint.h>
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
@@ skipping 180 matching lines @@
   if (rv != OK) {
     current_request_.reset();
     buffer_ = NULL;
     next_state_ = STATE_IDLE;
 
     return OK;
   }
 
   next_state_ = STATE_REQUEST_READING;
   int bytes_read = 0;
-  if (!current_request_->Read(buffer_.get(), kBufferSize, &bytes_read)) {
-    if (current_request_->status().is_io_pending())
-      return ERR_IO_PENDING;
+  current_request_->Read(buffer_.get(), kBufferSize, &bytes_read);
+  if (current_request_->status().is_io_pending())
+    return ERR_IO_PENDING;
 
-    if (current_request_->status().error() == OK) {
-      // This "should never happen", but if it does the result will be
-      // an infinite loop.  It's not clear how to handle a read failure
-      // without a promise to invoke the callback at some point in the future,
-      // so the request is failed.
-      SdchManager::SdchErrorRecovery(SdchManager::DICTIONARY_FETCH_READ_FAILED);
-      DLOG(FATAL)
-          << "URLRequest::Read() returned false without IO pending or error!";
-      return ERR_FAILED;
-    }
+  if (bytes_read < 0 || !current_request_->status().is_success()) {
+    if (current_request_->status().error() != OK)
+      return current_request_->status().error();
 
-    return current_request_->status().error();
+    // An error with request status of OK should not happen,
+    // but there's enough machinery underneath URLRequest::Read()
+    // that this routine checks for that case.
+    return (current_request_->status().status() ==
+            URLRequestStatus::CANCELED) ? ERR_ABORTED : ERR_FAILED;
   }
 
-  if (bytes_read != 0)
+  if (bytes_read == 0)
+    next_state_ = STATE_REQUEST_COMPLETE;
+  else
     dictionary_.append(buffer_->data(), bytes_read);
-  else
-    next_state_ = STATE_REQUEST_COMPLETE;
 
   return OK;
 }
 
 int SdchDictionaryFetcher::DoCompleteRequest(int rv) {
   DCHECK(CalledOnValidThread());
 
   // If the dictionary was successfully fetched, add it to the manager.
   if (rv == OK)
     dictionary_fetched_callback_.Run(dictionary_, current_request_->url());

[mmenke, 2014/11/17 15:24:58]

Should we be recording an error in UMA here?

 
   current_request_.reset();
   buffer_ = NULL;
   dictionary_.clear();
 
   next_state_ = STATE_IDLE;
 
   return OK;
 }
 
 }  // namespace net