Allow Offline MHTML save operations to succeed even with missing frames.

content/browser/download/mhtml_generation_manager.cc

 // Copyright (c) 2012 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/download/mhtml_generation_manager.h"
 
 #include <map>
 #include <queue>
 #include <utility>
 
@@ skipping 186 matching lines @@
 
     result[routing_id] = content_id;
   }
   return result;
 }
 
 MhtmlSaveStatus MHTMLGenerationManager::Job::SendToNextRenderFrame() {
   DCHECK(browser_file_.IsValid());
   DCHECK(!pending_frame_tree_node_ids_.empty());
 
+  int frame_tree_node_id = pending_frame_tree_node_ids_.front();
+  pending_frame_tree_node_ids_.pop();
+  FrameTreeNode* ftn = FrameTreeNode::GloballyFindByID(frame_tree_node_id);
+  if (!ftn) {  // A previously existing frame went away.
+    if (!params_.ignore_missing_frames)
+      return MhtmlSaveStatus::FRAME_NO_LONGER_EXISTS;
+    else if (pending_frame_tree_node_ids_.empty())
+      return MhtmlSaveStatus::SUCCESS;
+    else
+      return SendToNextRenderFrame();
+  }
+
   FrameMsg_SerializeAsMHTML_Params ipc_params;
   ipc_params.job_id = job_id_;
   ipc_params.mhtml_boundary_marker = mhtml_boundary_marker_;
   ipc_params.mhtml_binary_encoding = params_.use_binary_encoding;
   ipc_params.mhtml_cache_control_policy = params_.cache_control_policy;
-
-  int frame_tree_node_id = pending_frame_tree_node_ids_.front();
-  pending_frame_tree_node_ids_.pop();
   ipc_params.is_last_frame = pending_frame_tree_node_ids_.empty();
 
-  FrameTreeNode* ftn = FrameTreeNode::GloballyFindByID(frame_tree_node_id);
-  if (!ftn)  // The contents went away.
-    return MhtmlSaveStatus::FRAME_NO_LONGER_EXISTS;
   RenderFrameHost* rfh = ftn->current_frame_host();
 
   // Get notified if the target of the IPC message dies between responding.
   observed_renderer_process_host_.RemoveAll();
   observed_renderer_process_host_.Add(rfh->GetProcess());
 
   // Tell the renderer to skip (= deduplicate) already covered MHTML parts.
   ipc_params.salt = salt_;
   ipc_params.digests_of_uris_to_skip = digests_of_already_serialized_uris_;
 
@@ skipping 314 matching lines @@
   return iter->second.get();
 }
 
 void MHTMLGenerationManager::RenderProcessExited(Job* job) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   DCHECK(job);
   JobFinished(job, MhtmlSaveStatus::RENDER_PROCESS_EXITED);
 }
 
 }  // namespace content