base/prefs: Make use of ThreadCheck in favor of less inheritance.

TEST=base_unittests --gtest_filter=*Prefs*
R=mnissler@chromium.org,joi@chromium.org

Review URL: https://chromiumcodereview.appspot.com/14393002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@195517 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 8 insertions, 7 deletions

diff --git a/base/prefs/pref_notifier_impl.cc b/base/prefs/pref_notifier_impl.cc
index 1fa495d..c02a7b3 100644
--- a/base/prefs/pref_notifier_impl.cc
+++ b/base/prefs/pref_notifier_impl.cc
@@ -17,7 +17,7 @@ PrefNotifierImpl::PrefNotifierImpl(PrefService* service)
 }
 
 PrefNotifierImpl::~PrefNotifierImpl() {
-  DCHECK(CalledOnValidThread());
+  DCHECK(thread_checker_.CalledOnValidThread());
 
   // Verify that there are no pref observers when we shut down.
   for (PrefObserverMap::iterator it = pref_observers_.begin();
@@ -58,7 +58,7 @@ void PrefNotifierImpl::AddPrefObserver(const char* path,
 
 void PrefNotifierImpl::RemovePrefObserver(const char* path,
                                           PrefObserver* obs) {
-  DCHECK(CalledOnValidThread());
+  DCHECK(thread_checker_.CalledOnValidThread());
 
   const PrefObserverMap::iterator observer_iterator =
       pref_observers_.find(path);
@@ -79,7 +79,7 @@ void PrefNotifierImpl::OnPreferenceChanged(const std::string& path) {
 }
 
 void PrefNotifierImpl::OnInitializationCompleted(bool succeeded) {
-  DCHECK(CalledOnValidThread());
+  DCHECK(thread_checker_.CalledOnValidThread());
 
   // We must make a copy of init_observers_ and clear it before we run
   // observers, or we can end up in this method re-entrantly before
@@ -95,7 +95,7 @@ void PrefNotifierImpl::OnInitializationCompleted(bool succeeded) {
 }
 
 void PrefNotifierImpl::FireObservers(const std::string& path) {
-  DCHECK(CalledOnValidThread());
+  DCHECK(thread_checker_.CalledOnValidThread());
 
   // Only send notifications for registered preferences.
   if (!pref_service_->FindPreference(path.c_str()))
diff --git a/base/prefs/pref_notifier_impl.h b/base/prefs/pref_notifier_impl.h
index 8e6f090..8f5120a 100644
--- a/base/prefs/pref_notifier_impl.h
+++ b/base/prefs/pref_notifier_impl.h
@@ -15,14 +15,13 @@
 #include "base/prefs/base_prefs_export.h"
 #include "base/prefs/pref_notifier.h"
 #include "base/prefs/pref_observer.h"
-#include "base/threading/non_thread_safe.h"
+#include "base/threading/thread_checker.h"
 
 class PrefService;
 
 // The PrefNotifier implementation used by the PrefService.
 class BASE_PREFS_EXPORT PrefNotifierImpl
-    : public NON_EXPORTED_BASE(PrefNotifier),
-      public base::NonThreadSafe {
+    : public NON_EXPORTED_BASE(PrefNotifier) {
  public:
   PrefNotifierImpl();
   explicit PrefNotifierImpl(PrefService* pref_service);
@@ -66,6 +65,8 @@ class BASE_PREFS_EXPORT PrefNotifierImpl
   PrefObserverMap pref_observers_;
   PrefInitObserverList init_observers_;
 
+  base::ThreadChecker thread_checker_;
+
   DISALLOW_COPY_AND_ASSIGN(PrefNotifierImpl);
 };