Add TrackedPreferenceValidationDelegate

chrome/browser/prefs/tracked/tracked_atomic_preference.h

Index: chrome/browser/prefs/tracked/tracked_atomic_preference.h
diff --git a/chrome/browser/prefs/tracked/tracked_atomic_preference.h b/chrome/browser/prefs/tracked/tracked_atomic_preference.h
index 57422b1ba5f446e3ffb7585f26b61a973bb10e50..f55b76f6d29f008b4b5e86a1e1bcd6811fc82553 100644
--- a/chrome/browser/prefs/tracked/tracked_atomic_preference.h
+++ b/chrome/browser/prefs/tracked/tracked_atomic_preference.h
@@ -13,15 +13,18 @@
 #include "chrome/browser/prefs/tracked/tracked_preference.h"
 #include "chrome/browser/prefs/tracked/tracked_preference_helper.h"
 
+class TrackedPreferenceValidationDelegate;
+
 // A TrackedAtomicPreference is tracked as a whole. A hash is stored for its
-// entire value and it is entirely reset on mismatch.
+// entire value and it is entirely reset on mismatch. An optional delegate is
+// notified of the status of the preference during enforcement.
 class TrackedAtomicPreference : public TrackedPreference {
  public:
-  TrackedAtomicPreference(
-      const std::string& pref_path,
-      size_t reporting_id,
-      size_t reporting_ids_count,
-      PrefHashFilter::EnforcementLevel enforcement_level);
+  TrackedAtomicPreference(const std::string& pref_path,
+                          size_t reporting_id,
+                          size_t reporting_ids_count,
+                          PrefHashFilter::EnforcementLevel enforcement_level,
+                          TrackedPreferenceValidationDelegate* delegate);
 
   // TrackedPreference implementation.
   virtual void OnNewValue(const base::Value* value,
@@ -33,6 +36,7 @@ class TrackedAtomicPreference : public TrackedPreference {
  private:
   const std::string pref_path_;
   const TrackedPreferenceHelper helper_;
+  TrackedPreferenceValidationDelegate* delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(TrackedAtomicPreference);
 };