netlog: Don't enable recording if the "netlog" tracing category is disabled.

net/log/trace_net_log_observer_unittest.cc

 // Copyright 2014 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/log/trace_net_log_observer.h"
 
 #include <memory>
 #include <string>
 #include <vector>
 
@@ skipping 329 matching lines @@
   net_log()->AddGlobalEntry(NetLogEventType::URL_REQUEST_START_JOB);
 
   EndTraceAndFlush();
 
   TestNetLogEntry::List entries;
   net_log()->GetEntries(&entries);
   EXPECT_EQ(3u, entries.size());
   EXPECT_EQ(0u, trace_events()->GetSize());
 }
 
+TEST_F(TraceNetLogObserverTest, DisabledCategoryDoesntEnableNetLog) {
+  // Note: This test and the next one don't use the NetLog instance from the
+  // test fixture as it always has an observer, thus making the return value of
+  // NetLog::IsCapturing() not useful. This is still TEST_F(), as mixing TEST()
+  // and TEST_F() is not allowed.

[xunjieli, 2016/12/05 15:57:04]

This is okay. But alternatively you can use TEST instead of TEST_F under a
different test name. You can have different test names in a single unittest.cc
file. I think it's slightly cleaner that way and the tests are easier to read.

e.g. TEST(TraceNetLogCategoryTest, DisabledCategory)
and TEST(TraceNetLogCategoryTest, EnabledCategory)

[xunjieli, 2016/12/05 16:00:00]

And move these two tests either to the top or after the tests with TEST_F.

[Benoit L, 2016/12/05 16:44:25]

Done.

[Benoit L, 2016/12/05 16:44:25]

Done.

+  TraceNetLogObserver observer;
+  NetLog net_log;
+  observer.WatchForTraceStart(&net_log);
+
+  EXPECT_FALSE(net_log.IsCapturing());
+
+  std::string disabled_netlog_category =
+      std::string("-") + kNetLogTracingCategory;
+  TraceLog::GetInstance()->SetEnabled(
+      base::trace_event::TraceConfig(disabled_netlog_category, ""),
+      TraceLog::RECORDING_MODE);
+
+  EXPECT_FALSE(net_log.IsCapturing());
+  observer.StopWatchForTraceStart();
+  EXPECT_FALSE(net_log.IsCapturing());
+
+  TraceLog::GetInstance()->SetDisabled();
+}
+
+TEST_F(TraceNetLogObserverTest, CanEnableNetLog) {
+  TraceNetLogObserver observer;
+  NetLog net_log;
+  observer.WatchForTraceStart(&net_log);
+
+  EXPECT_FALSE(net_log.IsCapturing());
+
+  TraceLog::GetInstance()->SetEnabled(
+      base::trace_event::TraceConfig(kNetLogTracingCategory, ""),
+      TraceLog::RECORDING_MODE);
+
+  EXPECT_TRUE(net_log.IsCapturing());
+  observer.StopWatchForTraceStart();
+  EXPECT_FALSE(net_log.IsCapturing());
+
+  TraceLog::GetInstance()->SetDisabled();
+}
+
 TEST_F(TraceNetLogObserverTest, EventsWithAndWithoutParameters) {
   trace_net_log_observer()->WatchForTraceStart(net_log());
   EnableTraceLog();
   NetLogParametersCallback net_log_callback;
   std::string param = "bar";
   net_log_callback = NetLog::StringCallback("foo", &param);
 
   net_log()->AddGlobalEntry(NetLogEventType::CANCELLED, net_log_callback);
   net_log()->AddGlobalEntry(NetLogEventType::REQUEST_ALIVE);
 
@@ skipping 34 matching lines @@
   EXPECT_TRUE(item1->GetString("args.params.foo", &item1_params));
   EXPECT_EQ("bar", item1_params);
 
   EXPECT_TRUE(item2->GetString("args.params", &item2_params));
   EXPECT_TRUE(item2_params.empty());
 }
 
 }  // namespace
 
 }  // namespace net