ImportantFileWriter: check return value of PostTask...

chrome/browser/extensions/test_extension_prefs.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/test_extension_prefs.h"
 
 #include "base/file_util.h"
 #include "base/message_loop.h"
 #include "base/message_loop_proxy.h"
 #include "base/scoped_ptr.h"
 #include "base/values.h"
+#include "base/synchronization/waitable_event.h"
 #include "chrome/browser/extensions/extension_pref_store.h"
 #include "chrome/browser/extensions/extension_pref_value_map.h"
 #include "chrome/browser/extensions/extension_prefs.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/prefs/pref_service_mock_builder.h"
 #include "chrome/browser/prefs/pref_value_store.h"
 #include "chrome/common/extensions/extension.h"
 #include "chrome/common/extensions/extension_constants.h"
 #include "chrome/common/json_pref_store.h"
+#include "chrome/test/signaling_task.h"
 #include "content/browser/browser_thread.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace {
 
 // Mock ExtensionPrefs class with artificial clock to guarantee that no two
 // extensions get the same installation time stamp and we can reliably
 // assert the installation order in the tests below.
 class MockExtensionPrefs : public ExtensionPrefs {
  public:
@@ skipping 27 matching lines @@
 TestExtensionPrefs::~TestExtensionPrefs() {}
 
 void TestExtensionPrefs::RecreateExtensionPrefs() {
   // We persist and reload the PrefService's PrefStores because this process
   // deletes all empty dictionaries. The ExtensionPrefs implementation
   // needs to be able to handle this situation.
   if (pref_service_.get()) {
     // The PrefService writes its persistent file on the file thread, so we
     // need to wait for any pending I/O to complete before creating a new
     // PrefService.
-    MessageLoop file_loop;
-    BrowserThread file_thread(BrowserThread::FILE, &file_loop);
+    base::WaitableEvent io_finished(false, false);
     pref_service_->SavePersistentPrefs();
-    file_loop.RunAllPending();
+    EXPECT_TRUE(BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
+                                        new SignalingTask(&io_finished)));
+
+    // If the FILE thread is in fact the current thread (possible in testing
+    // scenarios), we have to ensure the task has a chance to run. If the FILE
+    // thread is a different thread, the test must ensure that thread is running
+    // (otherwise the Wait below will hang).
+    MessageLoop::current()->RunAllPending();
+
+    EXPECT_TRUE(io_finished.Wait());
   }
 
   extension_pref_value_map_.reset(new ExtensionPrefValueMap);
   PrefServiceMockBuilder builder;
   builder.WithUserFilePrefs(preferences_file_);
   builder.WithExtensionPrefs(
       new ExtensionPrefStore(extension_pref_value_map_.get(), false));
   pref_service_.reset(builder.Create());
   ExtensionPrefs::RegisterUserPrefs(pref_service_.get());
 
@@ skipping 30 matching lines @@
 
 std::string TestExtensionPrefs::AddExtensionAndReturnId(std::string name) {
   scoped_refptr<Extension> extension(AddExtension(name));
   return extension->id();
 }
 
 PrefService* TestExtensionPrefs::CreateIncognitoPrefService() const {
   return pref_service_->CreateIncognitoPrefService(
       new ExtensionPrefStore(extension_pref_value_map_.get(), true));
 }