Fix a race condition in preference metric reporting.

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 d9010a7ebfa1a7ca45657e62d4ef76a8035f7d77..8f34f660232fbb6602ed7ccb3c21595f6be605c1 100644
--- a/chrome/browser/profiles/profile_impl.cc
+++ b/chrome/browser/profiles/profile_impl.cc
@@ -60,6 +60,7 @@
 #include "chrome/browser/policy/profile_policy_connector_factory.h"
 #include "chrome/browser/prefs/browser_prefs.h"
 #include "chrome/browser/prefs/chrome_pref_service_factory.h"
+#include "chrome/browser/prefs/pref_hash_store_impl.h"
 #include "chrome/browser/prefs/pref_service_syncable.h"
 #include "chrome/browser/prerender/prerender_manager_factory.h"
 #include "chrome/browser/profiles/bookmark_model_loaded_observer.h"
@@ -92,6 +93,7 @@
 #include "content/public/browser/storage_partition.h"
 #include "content/public/browser/user_metrics.h"
 #include "content/public/common/content_constants.h"
+#include "grit/browser_resources.h"
 #include "grit/chromium_strings.h"
 #include "grit/generated_resources.h"
 #include "ui/base/l10n/l10n_util.h"
@@ -452,6 +454,11 @@ ProfileImpl::ProfileImpl(
         sequenced_task_runner,
         profile_policy_connector_->policy_service(),
         managed_user_settings,
+        scoped_ptr<PrefHashStore>(new PrefHashStoreImpl(

[robertshield, 2013/11/28 02:54:26]

Is there a benefit to wrapping this in a scoped pointer? It does make ownership
slightly clearer, but at the cost of a fair bit more boilerplate throughout the
places this is passed through.

[gab, 2013/11/28 04:12:03]

FWIW, I like the paradigm of passing via scoped_ptr when transferring ownership.
Being explicit about memory management is more important than less boilerplate
in this case IMO.

[erikwright (departed), 2013/11/28 17:48:07]

AFAIU, this is the new gold standard for documenting and enforcing ownership
transfer. And I, for one, welcome our movable overlords.

+            ResourceBundle::GetSharedInstance().GetRawDataResource(
+                IDR_PREF_HASH_SEED_BIN).as_string(),
+            g_browser_process->local_state(),
+            this->GetPath().AsUTF8Unsafe())),
         new ExtensionPrefStore(
             ExtensionPrefValueMapFactory::GetForBrowserContext(this), false),
         pref_registry_,