Add the ability to schedule any pending lossy prefs to be written.

base/prefs/persistent_pref_store.h

Index: base/prefs/persistent_pref_store.h
diff --git a/base/prefs/persistent_pref_store.h b/base/prefs/persistent_pref_store.h
index e70e2a677e1becd441a4aea253a4d00adda35f42..130bb9c483814d8c0849a05cc28aaa50bf2f29e9 100644
--- a/base/prefs/persistent_pref_store.h
+++ b/base/prefs/persistent_pref_store.h
@@ -67,6 +67,9 @@ class BASE_PREFS_EXPORT PersistentPrefStore : public WriteablePrefStore {
   // Lands any pending writes to disk.
   virtual void CommitPendingWrite() = 0;
 
+  // Schedule a write if there is any lossy data pending

[Mattias Nissler (ping if slow), 2015/05/28 07:20:24]

Nit: Missing period.

Also, would be nice to elaborate on the difference to CommitPendingWrite here,
i.e. that the latter does an immediate sync to disk, while
SchedulePendingLossyWrites() merely triggers an eventual write in case there
isn't one scheduled already.

[benwells, 2015/05/28 08:49:46]

Done.

+  virtual void SchedulePendingLossyWrites() = 0;
+
  protected:
   ~PersistentPrefStore() override {}
 };