Made the NavigationTracingObserver always be active whenever background tracing is active

chrome/browser/tracing/chrome_tracing_delegate_browsertest.cc

 // Copyright 2015 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/base_switches.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/prefs/pref_service.h"
 #include "chrome/app/chrome_command_ids.h"
 #include "chrome/browser/browser_process.h"
@@ skipping 210 matching lines @@
         switches::kForceFieldTrialParams,
         "BackgroundTracing.TestGroup:config/default_config_for_testing");
 
     tracing::SetConfigTextFilterForTesting(&FieldTrialConfigTextFilter);
   }
 };
 
 IN_PROC_BROWSER_TEST_F(ChromeTracingDelegateBrowserTestOnStartup,
                        ScenarioSetFromFieldtrial) {
   // We should reach this point without crashing.
-  EXPECT_TRUE(content::BackgroundTracingManager::GetInstance()
-                  ->HasActiveScenarioForTesting());
+  EXPECT_TRUE(
+      content::BackgroundTracingManager::GetInstance()->HasActiveScenario());
 }
 
 IN_PROC_BROWSER_TEST_F(ChromeTracingDelegateBrowserTestOnStartup,
                        PRE_StartupTracingThrottle) {
-  EXPECT_TRUE(content::BackgroundTracingManager::GetInstance()
-                  ->HasActiveScenarioForTesting());
+  EXPECT_TRUE(
+      content::BackgroundTracingManager::GetInstance()->HasActiveScenario());
 
   // Simulate a trace upload.
   PrefService* local_state = g_browser_process->local_state();
   DCHECK(local_state);
   local_state->SetInt64(prefs::kBackgroundTracingLastUpload,
                         base::Time::Now().ToInternalValue());
 }
 
 IN_PROC_BROWSER_TEST_F(ChromeTracingDelegateBrowserTestOnStartup,
                        StartupTracingThrottle) {
   // The startup scenario should *not* be started, since not enough
   // time has elapsed since the last upload (set in the PRE_ above).
-  EXPECT_FALSE(content::BackgroundTracingManager::GetInstance()
-                   ->HasActiveScenarioForTesting());
+  EXPECT_FALSE(
+      content::BackgroundTracingManager::GetInstance()->HasActiveScenario());
 }
 
 }  // namespace