Pref service: add support for tracked prefs.

chrome/browser/profiles/profile_impl.cc

Index: chrome/browser/profiles/profile_impl.cc
diff --git a/chrome/browser/profiles/profile_impl.cc b/chrome/browser/profiles/profile_impl.cc
index ceeacd8dcf205d8783e623ca736314e7275f6bad..0e6340d54882e17307f2bf2a0251ccfcbf8fdbcb 100644
--- a/chrome/browser/profiles/profile_impl.cc
+++ b/chrome/browser/profiles/profile_impl.cc
@@ -115,6 +115,7 @@
 #include "content/public/common/content_constants.h"
 #include "content/public/common/page_zoom.h"
 #include "extensions/features/features.h"
+#include "mojo/public/cpp/bindings/strong_binding.h"
 #include "ppapi/features/features.h"
 #include "printing/features/features.h"
 #include "services/identity/identity_service.h"
@@ -485,9 +486,14 @@ ProfileImpl::ProfileImpl(
 
   scoped_refptr<safe_browsing::SafeBrowsingService> safe_browsing_service(
       g_browser_process->safe_browsing_service());
+  prefs::mojom::TrackedPreferenceValidationDelegatePtr pref_validation_delegate;
   if (safe_browsing_service.get()) {
-    pref_validation_delegate_ =
+    auto pref_validation_delegate_impl =
         safe_browsing_service->CreatePreferenceValidationDelegate(this);
+    if (pref_validation_delegate_impl) {
+      mojo::MakeStrongBinding(std::move(pref_validation_delegate_impl),
+                              mojo::MakeRequest(&pref_validation_delegate));
+    }
   }
 
   content::BrowserContext::Initialize(this, path_);
@@ -498,7 +504,7 @@ ProfileImpl::ProfileImpl(
       connector = content::BrowserContext::GetConnectorFor(this);
     }
     prefs_ = chrome_prefs::CreateProfilePrefs(
-        path_, sequenced_task_runner, pref_validation_delegate_.get(),
+        path_, std::move(pref_validation_delegate),
         profile_policy_connector_->policy_service(), supervised_user_settings,
         CreateExtensionPrefStore(this, false), pref_registry_, async_prefs,
         connector);