[HttpCache] Store some memcache info to memory dumps for debugging

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 <stdint.h>
 
 #include "base/files/file.h"
 #include "base/files/file_util.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/field_trial.h"
 #include "base/run_loop.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/test/mock_entropy_provider.h"
 #include "base/third_party/dynamic_annotations/dynamic_annotations.h"
 #include "base/threading/platform_thread.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/threading/thread_task_runner_handle.h"
-#include "base/trace_event/memory_usage_estimator.h"
+#include "base/trace_event/process_memory_dump.h"
 #include "net/base/cache_type.h"
 #include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
 #include "net/base/test_completion_callback.h"
 #include "net/disk_cache/blockfile/backend_impl.h"
 #include "net/disk_cache/blockfile/entry_impl.h"
 #include "net/disk_cache/blockfile/experiments.h"
 #include "net/disk_cache/blockfile/histogram_macros.h"
 #include "net/disk_cache/blockfile/mapped_file.h"
 #include "net/disk_cache/cache_util.h"
@@ skipping 285 matching lines @@
 }
 
 void DiskCacheBackendTest::BackendBasics() {
   InitCache();
   disk_cache::Entry *entry1 = NULL, *entry2 = NULL;
   EXPECT_NE(net::OK, OpenEntry("the first key", &entry1));
   ASSERT_THAT(CreateEntry("the first key", &entry1), IsOk());
   ASSERT_TRUE(NULL != entry1);
   entry1->Close();
   entry1 = NULL;
   // base::trace_event::EstimateMemoryUsage(cache_) is added to make sure

[ssid, 2017/03/27 18:59:41]

Is this comment still valid?

[jkarlin, 2017/03/28 15:09:45]

Removed.

   // tracking memory doesn't introduce crashes.
-  EXPECT_LT(0u, base::trace_event::EstimateMemoryUsage(cache_));
+  base::trace_event::MemoryDumpArgs args = {
+      base::trace_event::MemoryDumpLevelOfDetail::DETAILED};

[xunjieli, 2017/03/27 18:29:06]

Could you run this with base::trace_event::MemoryDumpLevelOfDetail::BACKGROUND ?

If you do that, you can pass parent_absolute_name =
"net/url_request_context_0x123/http_cache" (or
"net/url_request_context/main/0x123/http_cache" if my CL lands before yours) to
cache_->DumpMemoryStats()

The BACKGROUND mode will additionally assert that any sub dumps created will be
whitelisted.

[jkarlin, 2017/03/28 15:09:45]

Done, and broke it out into separate tests.

+  base::trace_event::ProcessMemoryDump pmd(nullptr, args);
+  ASSERT_LT(0u, cache_->DumpMemoryStats(&pmd, ""));
+  EXPECT_LT(0u, pmd.allocator_dumps().size());
 
   ASSERT_THAT(OpenEntry("the first key", &entry1), IsOk());
   ASSERT_TRUE(NULL != entry1);
   entry1->Close();
   entry1 = NULL;
 
   EXPECT_NE(net::OK, CreateEntry("the first key", &entry1));
   ASSERT_THAT(OpenEntry("the first key", &entry1), IsOk());
   EXPECT_NE(net::OK, OpenEntry("some other key", &entry2));
   ASSERT_THAT(CreateEntry("some other key", &entry2), IsOk());
   ASSERT_TRUE(NULL != entry1);
   ASSERT_TRUE(NULL != entry2);
   EXPECT_EQ(2, cache_->GetEntryCount());
-  EXPECT_LT(0u, base::trace_event::EstimateMemoryUsage(cache_));
+  base::trace_event::ProcessMemoryDump pmd2(nullptr, args);
+  ASSERT_LT(0u, cache_->DumpMemoryStats(&pmd2, ""));
+  EXPECT_LT(0u, pmd2.allocator_dumps().size());
 
   disk_cache::Entry* entry3 = NULL;
   ASSERT_THAT(OpenEntry("some other key", &entry3), IsOk());
   ASSERT_TRUE(NULL != entry3);
   EXPECT_TRUE(entry2 == entry3);
-  EXPECT_LT(0u, base::trace_event::EstimateMemoryUsage(cache_));
 
   EXPECT_THAT(DoomEntry("some other key"), IsOk());
   EXPECT_EQ(1, cache_->GetEntryCount());
   entry1->Close();
   entry2->Close();
   entry3->Close();
-  EXPECT_LT(0u, base::trace_event::EstimateMemoryUsage(cache_));
 
   EXPECT_THAT(DoomEntry("the first key"), IsOk());
   EXPECT_EQ(0, cache_->GetEntryCount());
 
   ASSERT_THAT(CreateEntry("the first key", &entry1), IsOk());
   ASSERT_THAT(CreateEntry("some other key", &entry2), IsOk());
   entry1->Doom();
   entry1->Close();
   EXPECT_THAT(DoomEntry("some other key"), IsOk());
   EXPECT_EQ(0, cache_->GetEntryCount());
   entry2->Close();
-  EXPECT_LT(0u, base::trace_event::EstimateMemoryUsage(cache_));
 }
 
 TEST_F(DiskCacheBackendTest, Basics) {
   BackendBasics();
 }
 
 TEST_F(DiskCacheBackendTest, NewEvictionBasics) {
   SetNewEviction();
   BackendBasics();
 }
@@ skipping 3549 matching lines @@
   // because that would advance the cache directory mtime and invalidate the
   // index.
   entry2->Doom();
   entry2->Close();
 
   DisableFirstCleanup();
   InitCache();
   EXPECT_EQ(disk_cache::SimpleIndex::INITIALIZE_METHOD_LOADED,
             simple_cache_impl_->index()->init_method());
 }