Integrate registry_hash_store_contents with the rest of tracked prefs.

base/files/important_file_writer.h

Index: base/files/important_file_writer.h
diff --git a/base/files/important_file_writer.h b/base/files/important_file_writer.h
index 0bd8a7fd358f037ba26a8768a46b55627a112be3..577bb5ea8eaf3b1aaa04b48d41473ded78908219 100644
--- a/base/files/important_file_writer.h
+++ b/base/files/important_file_writer.h
@@ -95,10 +95,16 @@ class BASE_EXPORT ImportantFileWriter : public NonThreadSafe {
   // Serialize data pending to be saved and execute write on backend thread.
   void DoScheduledWrite();
 
-  // Registers |on_next_successful_write| to be called once, on the next
-  // successful write event. Only one callback can be set at once.
-  void RegisterOnNextSuccessfulWriteCallback(
-      const Closure& on_next_successful_write);
+  // Registers |on_next_successful_write_reply| to be invoked on the sequence
+  // owning this ImportantFileWriter in reply to the next successful write.

[gab, 2016/08/08 04:37:44]

+ "Only one such callback can be set at once."

here and below

[proberge, 2016/08/31 17:30:15]

Done.

+  void RegisterOnNextSuccessfulWriteReply(

[gab, 2016/08/08 04:37:44]

Need to update important_file_writer_unittest.cc

[proberge, 2016/08/31 17:30:15]

Done.

+      const Closure& on_next_successful_write_reply);
+
+  // Registers |on_next_write_callback| to be synchronously invoked from
+  // WriteFileAtomically() on its next write (i.e. from |task_runner_|), with
+  // |success| indicating whether it succeeded or not.
+  void RegisterOnNextWriteSynchronousCallback(

[gab, 2016/08/08 04:37:44]

Update CL description to explain why this is required (for the eventual base
owner reviewing this' sake)

[proberge, 2016/08/31 17:30:15]

Acknowledged. Will be done in precursor CL.

+      const Callback<void(bool success)>& on_next_write_callback);

[gab, 2016/08/08 04:37:44]

Add test in important_file_writer_unittest.cc

[proberge, 2016/08/31 17:30:15]

Done.

 
   TimeDelta commit_interval() const {
     return commit_interval_;
@@ -113,7 +119,10 @@ class BASE_EXPORT ImportantFileWriter : public NonThreadSafe {
   void ForwardSuccessfulWrite(bool result);
 
   // Invoked once and then reset on the next successful write event.
-  Closure on_next_successful_write_;
+  Closure on_next_successful_write_reply_;
+
+  // Invoked synchronously on the next write event.
+  Callback<void(bool success)> on_next_write_callback_;
 
   // Path being written to.
   const FilePath path_;