Make FileStream::Seek async and add FileStream::SeekSync for sync operation

net/http/http_cache_unittest.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 "net/http/http_cache.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/memory/scoped_vector.h"
 #include "base/message_loop.h"
@@ skipping 15 matching lines @@
 #include "net/http/http_transaction.h"
 #include "net/http/http_transaction_unittest.h"
 #include "net/http/http_util.h"
 #include "net/http/mock_http_cache.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using base::Time;
 
 namespace {
 
-class DeleteCacheCompletionCallback : public TestCompletionCallbackBase {
+class DeleteCacheCompletionCallback : public net::TestCompletionCallbackBase {
  public:
   explicit DeleteCacheCompletionCallback(MockHttpCache* cache)
       : cache_(cache),
         ALLOW_THIS_IN_INITIALIZER_LIST(callback_(
             base::Bind(&DeleteCacheCompletionCallback::OnComplete,
                        base::Unretained(this)))) {
   }
 
   const net::CompletionCallback& callback() const { return callback_; }
 
@@ skipping 4768 matching lines @@
 
   // Verify that the entry is marked as incomplete.
   disk_cache::Entry* entry;
   ASSERT_TRUE(cache.OpenBackendEntry(kSimpleGET_Transaction.url, &entry));
   net::HttpResponseInfo response;
   bool truncated = false;
   EXPECT_TRUE(MockHttpCache::ReadResponseInfo(entry, &response, &truncated));
   EXPECT_TRUE(truncated);
   entry->Close();
 }