Update NavigationHandleImpl#GetResponseHeaders method.

content/browser/frame_host/navigation_handle_impl.cc

 // Copyright 2015 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 "content/browser/frame_host/navigation_handle_impl.h"
 
 #include <utility>
 
 #include "content/browser/frame_host/frame_tree_node.h"
 #include "content/browser/frame_host/navigator.h"
@@ skipping 115 matching lines @@
 }
 
 bool NavigationHandleImpl::IsSamePage() {
   DCHECK(state_ == DID_COMMIT || state_ == DID_COMMIT_ERROR_PAGE)
       << "This accessor should not be called before the navigation has "
          "committed.";
   return is_same_page_;
 }
 
 const net::HttpResponseHeaders* NavigationHandleImpl::GetResponseHeaders() {
-  DCHECK(state_ >= WILL_REDIRECT_REQUEST)
-      << "This accessor should only be called when the request encountered a "
-         "redirect or received a response";
    return response_headers_.get();
 }
 
 bool NavigationHandleImpl::HasCommitted() {
   return state_ == DID_COMMIT || state_ == DID_COMMIT_ERROR_PAGE;
 }
 
 bool NavigationHandleImpl::IsErrorPage() {
   return state_ == DID_COMMIT_ERROR_PAGE;
 }
@@ skipping 296 matching lines @@
   complete_callback_.Reset();
 
   if (!callback.is_null())
     callback.Run(result);
 
   // No code after running the callback, as it might have resulted in our
   // destruction.
 }
 
 }  // namespace content