Fix Simple Cache race on multiple dooms in flight.

net/disk_cache/entry_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 "base/basictypes.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/file_util.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
@@ skipping 3067 matching lines @@
   net::TestCompletionCallback cb;
   EXPECT_EQ(net::OK,
             cb.GetResult(simple_entry1->DoomEntry(cb.callback())));
 
   disk_cache::Entry* entry3 = NULL;
   ASSERT_EQ(net::OK, OpenEntry(key, &entry3));
   ScopedEntryPtr entry3_closer(entry3);
   EXPECT_NE(null, entry3);
 }
 
+TEST_F(DiskCacheEntryTest, SimpleCacheDoomCreateDoom) {
+  // Test sequence:
+  // Create, Doom, Create, Doom.

[pasko, 2013/09/16 14:01:42]

nit: I would have written this with more clarity:
// Test sequence for operations on the same key:
// Create(entry1), Doom(entry1), Create(entry2), Doom(entry2).

not very important, the test is short and clear anyway

+  SetSimpleCacheMode();
+  InitCache();
+
+  disk_cache::Entry* null = NULL;
+
+  const char key[] = "the first key";
+
+  disk_cache::Entry* entry1 = NULL;
+  ASSERT_EQ(net::OK, CreateEntry(key, &entry1));
+  ScopedEntryPtr entry1_closer(entry1);
+  EXPECT_NE(null, entry1);
+
+  entry1->Doom();
+
+  disk_cache::Entry* entry2 = NULL;
+  ASSERT_EQ(net::OK, CreateEntry(key, &entry2));
+  ScopedEntryPtr entry2_closer(entry2);
+  EXPECT_NE(null, entry2);
+
+  entry2->Doom();
+
+  // This test passes if it doesn't crash.
+}
+
 // Checks that an optimistic Create would fail later on a racing Open.
 TEST_F(DiskCacheEntryTest, SimpleCacheOptimisticCreateFailsOnOpen) {
   SetSimpleCacheMode();
   InitCache();
 
   // Create a corrupt file in place of a future entry. Optimistic create should
   // initially succeed, but realize later that creation failed.
   const std::string key = "the key";
   net::TestCompletionCallback cb;
   disk_cache::Entry* entry = NULL;
@@ skipping 351 matching lines @@
 
   // Check that we are not leaking.
   ASSERT_NE(entry, null);
   EXPECT_TRUE(
       static_cast<disk_cache::SimpleEntryImpl*>(entry)->HasOneRef());
   entry->Close();
   entry = NULL;
 }
 
 #endif  // defined(OS_POSIX)