Avoid calling Abort from main thread on IBinding created on another thread. I...

plugin/npapi_host_control/win/stream_operation.cc

 // Copyright 2009, Google Inc.  All rights reserved.
 // Portions of this file were adapted from the Mozilla project.
 // See https://developer.mozilla.org/en/ActiveX_Control_for_Hosting_Netscape_Plug-ins_in_IE
 /* ***** BEGIN LICENSE BLOCK *****
  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
  *
  * The contents of this file are subject to the Mozilla Public License Version
  * 1.1 (the "License"); you may not use this file except in compliance with
  * the License. You may obtain a copy of the License at
  * http://www.mozilla.org/MPL/
@@ skipping 249 matching lines @@
 }
 
 HRESULT STDMETHODCALLTYPE StreamOperation::OnLowResource(DWORD reserved) {
   return S_OK;
 }
 
 HRESULT STDMETHODCALLTYPE StreamOperation::OnProgress(ULONG ulProgress,
                                                       ULONG ulProgressMax,
                                                       ULONG ulStatusCode,
                                                       LPCWSTR szStatusText) {
+  if (cancel_requested_) {
+    binding_->Abort();
+    return S_OK;
+  }
+
   // Capture URL re-directs and MIME-type status notifications.
   switch (ulStatusCode) {
     case BINDSTATUS_BEGINDOWNLOADDATA:
     case BINDSTATUS_REDIRECTING:
       url_ = szStatusText;
       break;
     case BINDSTATUS_MIMETYPEAVAILABLE:
       content_type_ = szStatusText;
       break;
     default:
@@ skipping 79 matching lines @@
     DWORD grfBSCF,
     DWORD dwSize,
     FORMATETC *pformatetc,
     STGMEDIUM *pstgmed) {
   if (pstgmed->tymed != TYMED_ISTREAM || !pstgmed->pstm) {
     return S_OK;
   }
 
   // Don't bother processing any data if the stream has been canceled.
   if (cancel_requested_) {
+    binding_->Abort();
     return S_OK;
   }
 
   // Notify the plugin that a new stream has been opened.
   if (grfBSCF & BSCF_FIRSTDATANOTIFICATION) {
     USES_CONVERSION;
     np_stream_.url = W2CA(url_);
     np_stream_.end = stream_size_;
     np_stream_.lastmodified = 0;
     np_stream_.notifyData = GetNotifyData();
@@ skipping 363 matching lines @@
     HANDLE* event_handle = reinterpret_cast<HANDLE*>(wParam);
     SetEvent(*event_handle);
   }
   return 0;
 }
 
 HRESULT StreamOperation::RequestCancellation() {
   ATLASSERT(binding_ &&
             "Cancellation request on a stream that has not been bound.");
   cancel_requested_ = true;
-  if (binding_) {
-    return binding_->Abort();
-  }
   return S_OK;
 }