Don't abort the MimeHandlerStreamManager stream if we receive a RenderProcessHostChanged notificati…

content/browser/web_contents/web_contents_impl.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/web_contents/web_contents_impl.h"
 
 #include <stddef.h>
 
 #include <cmath>
 #include <utility>
@@ skipping 290 matching lines @@
 
 WebContents* WebContents::FromRenderFrameHost(RenderFrameHost* rfh) {
   if (!rfh)
     return nullptr;
   return static_cast<RenderFrameHostImpl*>(rfh)->delegate()->GetAsWebContents();
 }
 
 WebContents* WebContents::FromFrameTreeNodeId(int frame_tree_node_id) {
   FrameTreeNode* frame_tree_node =
       FrameTreeNode::GloballyFindByID(frame_tree_node_id);
+  if (!frame_tree_node)
+    return nullptr;
   return FromRenderFrameHost(frame_tree_node->current_frame_host());
 }
 
 // WebContentsImpl::DestructionObserver ----------------------------------------
 
 class WebContentsImpl::DestructionObserver : public WebContentsObserver {
  public:
   DestructionObserver(WebContentsImpl* owner, WebContents* watched_contents)
       : WebContentsObserver(watched_contents),
         owner_(owner) {
@@ skipping 4951 matching lines @@
   dialog_manager_ = dialog_manager;
 }
 
 void WebContentsImpl::RemoveBindingSet(const std::string& interface_name) {
   auto it = binding_sets_.find(interface_name);
   if (it != binding_sets_.end())
     binding_sets_.erase(it);
 }
 
 }  // namespace content