Refactored app cache clear on exit code to happen in the object owning the files.

chrome/browser/appcache/chrome_appcache_service_unittest.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 "base/file_util.h"
+#include "base/message_loop.h"
+#include "base/ref_counted.h"
+#include "base/scoped_temp_dir.h"
+#include "chrome/browser/appcache/chrome_appcache_service.h"
+#include "chrome/browser/browser_thread.h"
+#include "chrome/common/chrome_constants.h"
+#include "chrome/test/thread_test_helper.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+class ChromeAppCacheServiceTest : public testing::Test {
+ public:
+  ChromeAppCacheServiceTest()
+      : db_thread_(BrowserThread::DB, &message_loop_),
+        file_thread_(BrowserThread::FILE, &message_loop_),
+        io_thread_(BrowserThread::IO, &message_loop_) {
+  }
+
+ protected:
+  MessageLoop message_loop_;
+  ScopedTempDir temp_dir_;
+
+ private:
+  BrowserThread db_thread_;
+  BrowserThread file_thread_;
+  BrowserThread io_thread_;
+};
+
+TEST_F(ChromeAppCacheServiceTest, KeepOnDestruction) {
+  ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
+  FilePath appcache_path = temp_dir_.path().Append(chrome::kAppCacheDirname);
+  scoped_refptr<ChromeAppCacheService> appcache_service =
+      new ChromeAppCacheService;
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      NewRunnableMethod(appcache_service.get(),
+                        &ChromeAppCacheService::InitializeOnIOThread,
+                        temp_dir_.path(), false,
+                        scoped_refptr<HostContentSettingsMap>(NULL),
+                        false));
+  // Create some fake cache index.
+  ASSERT_TRUE(file_util::CreateDirectory(appcache_path));
+  ASSERT_EQ(0, file_util::WriteFile(
+      appcache_path.AppendASCII("Index"), NULL, 0));
+
+  appcache_service = NULL;
+  message_loop_.RunAllPending();
+
+  ASSERT_TRUE(file_util::PathExists(appcache_path));
+}
+
+TEST_F(ChromeAppCacheServiceTest, RemoveOnDestruction) {

[michaeln, 2011/01/05 21:03:05]

The ChromeAppCacheService code looks great, I like keeping this at the /chrome
level too. But I wonder if the test can be made better such that it actually
tests the full shutdown sequence including the closing of open database and
disk_cache files.

Question: Have you observed the deletion working properly when the files are
actually open upon dtor invocation, particularly on windows where opened files
can't be deleted?

The test right now demonstrates that DeleteDir is called on the directory, but
does not verify that this actually works when the appcache service has it's
files open (since it opens them lazily). Setting up that that precondition would
be a little tricky...

* you could call AppCacheDatabase::LazyOpen(true) to open the db file
* poke 0 into AppCacheStorageImpl::last_cache_id_ (to convince the storage impl
that its initialized)
* invoke AppCacheStorageImpl::disk_cache() to get that initted. But that is
actually async under the covers, it happens on the CACHE_THREAD so you may need
another BrowserThread for that.
* call RunAllPending() so the disk_cache() init is really done
* check for the existence of the Index file and Cache subdirectory
* finally... release the service instance to trigger destruction

[pastarmovj, 2011/01/07 13:28:21]

Done.

+  ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
+  FilePath appcache_path = temp_dir_.path().Append(chrome::kAppCacheDirname);
+  scoped_refptr<ChromeAppCacheService> appcache_service =
+      new ChromeAppCacheService;
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      NewRunnableMethod(appcache_service.get(),
+                        &ChromeAppCacheService::InitializeOnIOThread,
+                        temp_dir_.path(), false,
+                        scoped_refptr<HostContentSettingsMap>(NULL),
+                        true));
+  // Create some fake cache index.
+  ASSERT_TRUE(file_util::CreateDirectory(appcache_path));
+  ASSERT_EQ(0, file_util::WriteFile(
+      appcache_path.AppendASCII("Index"), NULL, 0));
+
+  appcache_service = NULL;
+  message_loop_.RunAllPending();
+
+  ASSERT_FALSE(file_util::PathExists(appcache_path));
+}
+
+}  // namespace