Clean up dependencies for disk_cache histogram_macros.h.

net/disk_cache/backend_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/file_util.h"
 #include "base/metrics/field_trial.h"
 #include "base/port.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
@@ skipping 17 matching lines @@
 #include "net/disk_cache/simple/simple_entry_format.h"
 #include "net/disk_cache/simple/simple_test_util.h"
 #include "net/disk_cache/simple/simple_util.h"
 #include "net/disk_cache/tracing_cache_backend.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 #if defined(OS_WIN)
 #include "base/win/scoped_handle.h"
 #endif
 
+// Provide a BackendImpl object to macros from histogram_macros.h.
+#define CACHE_UMA_BACKEND_IMPL_OBJ backend_
+
 using base::Time;
 
 namespace {
 
 const char kExistingEntryKey[] = "existing entry key";
 
 scoped_ptr<disk_cache::BackendImpl> CreateExistingEntryCache(
     const base::Thread& cache_thread,
     base::FilePath& cache_path) {
   net::TestCompletionCallback cb;
@@ skipping 3437 matching lines @@
   void* iter = NULL;
   size_t count = 0;
   ASSERT_TRUE(EnumerateAndMatchKeys(-1, &iter, &keys_to_match, &count));
   cache_->EndEnumeration(&iter);
 
   EXPECT_EQ(key_pool.size(), count);
   EXPECT_TRUE(keys_to_match.empty());
 }
 
 #endif  // defined(OS_POSIX)