Fix race condition in utility process clients

chrome/browser/extensions/webstore_install_helper.cc

 // Copyright (c) 2011 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 "chrome/browser/extensions/webstore_install_helper.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/values.h"
@@ skipping 17 matching lines @@
     const std::string& manifest,
     const std::string& icon_data,
     const GURL& icon_url,
     net::URLRequestContextGetter* context_getter)
     : delegate_(delegate),
       id_(id),
       manifest_(manifest),
       icon_base64_data_(icon_data),
       icon_url_(icon_url),
       context_getter_(context_getter),
-      utility_host_(NULL),
       icon_decode_complete_(false),
       manifest_parse_complete_(false),
       parse_error_(Delegate::UNKNOWN_ERROR) {}
 
 WebstoreInstallHelper::~WebstoreInstallHelper() {}
 
 void WebstoreInstallHelper::Start() {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   CHECK(icon_base64_data_.empty() || icon_url_.is_empty());
 
@@ skipping 11 matching lines @@
         icon_url_, content::URLFetcher::GET, this));
     url_fetcher_->SetRequestContext(context_getter_);
 
     url_fetcher_->Start();
     // We'll get called back in OnURLFetchComplete.
   }
 }
 
 void WebstoreInstallHelper::StartWorkOnIOThread() {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  utility_host_ = new UtilityProcessHost(this, BrowserThread::IO);
+  utility_host_ =
+      (new UtilityProcessHost(this, BrowserThread::IO))->AsWeakPtr();
   utility_host_->set_use_linux_zygote(true);
   utility_host_->StartBatchMode();
 
   if (!icon_base64_data_.empty())
     utility_host_->Send(
         new ChromeUtilityMsg_DecodeImageBase64(icon_base64_data_));
 
   utility_host_->Send(new ChromeUtilityMsg_ParseJSON(manifest_));
 }
 
@@ skipping 84 matching lines @@
   ReportResultsIfComplete();
 }
 
 void WebstoreInstallHelper::ReportResultsIfComplete() {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
   if (!icon_decode_complete_ || !manifest_parse_complete_)
     return;
 
   // The utility_host_ will take care of deleting itself after this call.
-  utility_host_->EndBatchMode();
-  utility_host_ = NULL;
+  if (utility_host_) {
+    utility_host_->EndBatchMode();
+    utility_host_.reset();
+  }
 
   BrowserThread::PostTask(
       BrowserThread::UI,
       FROM_HERE,
       base::Bind(&WebstoreInstallHelper::ReportResultFromUIThread, this));
 }
 
 void WebstoreInstallHelper::ReportResultFromUIThread() {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   if (error_.empty() && parsed_manifest_.get())
     delegate_->OnWebstoreParseSuccess(id_, icon_, parsed_manifest_.release());
   else
     delegate_->OnWebstoreParseFailure(id_, parse_error_, error_);
 }