Switch DCHECK() guarding against URLRequest::Read() failure

net/base/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/base/sdch_dictionary_fetcher.h"
 
 #include <stdint.h>
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
@@ skipping 185 matching lines @@
 
     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;
 
-    DCHECK_NE(current_request_->status().error(), OK);
     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;
     }
 
     return current_request_->status().error();
   }
 
   if (bytes_read != 0)
     dictionary_.append(buffer_->data(), bytes_read);
   else
     next_state_ = STATE_REQUEST_COMPLETE;
@@ skipping 11 matching lines @@
   current_request_.reset();
   buffer_ = NULL;
   dictionary_.clear();
 
   next_state_ = STATE_IDLE;
 
   return OK;
 }
 
 }  // namespace net