Content Verification: Don't access UI-thread objects on the IO thread

chrome/browser/extensions/user_script_master.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 "chrome/browser/extensions/user_script_master.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 21 matching lines @@
 using extensions::ExtensionsBrowserClient;
 
 namespace extensions {
 
 namespace {
 
 typedef base::Callback<void(scoped_ptr<UserScriptList>,
                             scoped_ptr<base::SharedMemory>)>
                                 LoadScriptsCallback;
 
 void VerifyContent(scoped_refptr<ContentVerifier> verifier,

[Ken Rockot(use gerrit already), 2014/07/22 16:44:22]

Could you DCHECK that you're on the IO thread here? Mostly for documentation.

[asargent_no_longer_on_chrome, 2014/07/22 20:27:28]

Done.

                    const std::string& extension_id,
                    const base::FilePath& extension_root,
                    const base::FilePath& relative_path,
                    const std::string& content) {
   scoped_refptr<ContentVerifyJob> job(
       verifier->CreateJobFor(extension_id, extension_root, relative_path));
   if (job.get()) {
     job->Start();
     job->BytesRead(content.size(), content.data());
     job->DoneReading();
@@ skipping 21 matching lines @@
                    << script_file->relative_path().value() << " from "
                    << script_file->extension_root().value();
       return false;
     }
   } else {
     if (!base::ReadFileToString(path, &content)) {
       LOG(WARNING) << "Failed to load user script file: " << path.value();
       return false;
     }
     if (verifier) {
-      VerifyContent(verifier,
-                    extension_id,
-                    script_file->extension_root(),
-                    script_file->relative_path(),
-                    content);
+      content::BrowserThread::PostTask(content::BrowserThread::IO,
+                                       FROM_HERE,
+                                       base::Bind(&VerifyContent,
+                                                  verifier,
+                                                  extension_id,
+                                                  script_file->extension_root(),
+                                                  script_file->relative_path(),
+                                                  content));
     }
   }
 
   // Localize the content.
   if (localization_messages) {
     std::string error;
     MessageBundle::ReplaceMessagesWithExternalDictionary(
         *localization_messages, &content, &error);
     if (!error.empty()) {
       LOG(WARNING) << "Failed to replace messages in script: " << error;
@@ skipping 440 matching lines @@
   if (!shared_memory->ShareToProcess(handle, &handle_for_process))
     return;  // This can legitimately fail if the renderer asserts at startup.
 
   if (base::SharedMemory::IsHandleValid(handle_for_process)) {
     process->Send(new ExtensionMsg_UpdateUserScripts(handle_for_process,
                                                      changed_extensions));
   }
 }
 
 }  // namespace extensions