Moved JsonPrefStore to use SequencedWorkerPool instead of FILE thread. The pool also ensures that the same file requests are written in order received and that they block on shutdown.

BUG=153367
TEST=existing unit/browser tests

Review URL: https://codereview.chromium.org/11027070

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@166603 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 12 insertions, 12 deletions

diff --git a/base/files/important_file_writer.cc b/base/files/important_file_writer.cc
index 5663bdd..536b0fb 100644
--- a/base/files/important_file_writer.cc
+++ b/base/files/important_file_writer.cc
@@ -13,7 +13,7 @@
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/logging.h"
-#include "base/message_loop_proxy.h"
+#include "base/task_runner.h"
 #include "base/metrics/histogram.h"
 #include "base/string_number_conversions.h"
 #include "base/threading/thread.h"
@@ -90,14 +90,14 @@ void WriteToDiskTask(const FilePath& path, const std::string& data) {
 }  // namespace
 
 ImportantFileWriter::ImportantFileWriter(
-    const FilePath& path, MessageLoopProxy* file_message_loop_proxy)
+    const FilePath& path, base::SequencedTaskRunner* task_runner)
         : path_(path),
-          file_message_loop_proxy_(file_message_loop_proxy),
+          task_runner_(task_runner),
           serializer_(NULL),
           commit_interval_(TimeDelta::FromMilliseconds(
               kDefaultCommitIntervalMs)) {
   DCHECK(CalledOnValidThread());
-  DCHECK(file_message_loop_proxy_.get());
+  DCHECK(task_runner_.get());
 }
 
 ImportantFileWriter::~ImportantFileWriter() {
@@ -122,8 +122,8 @@ void ImportantFileWriter::WriteNow(const std::string& data) {
   if (HasPendingWrite())
     timer_.Stop();
 
-  if (!file_message_loop_proxy_->PostTask(
-      FROM_HERE, MakeCriticalClosure(Bind(&WriteToDiskTask, path_, data)))) {
+  if (!task_runner_->PostTask(FROM_HERE,
+          MakeCriticalClosure(Bind(&WriteToDiskTask, path_, data)))) {
     // Posting the task to background message loop is not expected
     // to fail, but if it does, avoid losing data and just hit the disk
     // on the current thread.
diff --git a/base/files/important_file_writer.h b/base/files/important_file_writer.h
index 290813c..ae814d5 100644
--- a/base/files/important_file_writer.h
+++ b/base/files/important_file_writer.h
@@ -17,7 +17,7 @@
 
 namespace base {
 
-class MessageLoopProxy;
+class SequencedTaskRunner;
 class Thread;
 
 // Helper to ensure that a file won't be corrupted by the write (for example on
@@ -53,11 +53,11 @@ class BASE_EXPORT ImportantFileWriter : public NonThreadSafe {
 
   // Initialize the writer.
   // |path| is the name of file to write.
-  // |file_message_loop_proxy| is the MessageLoopProxy for a thread on which
-  // file I/O can be done.
+  // |task_runner| is the SequencedTaskRunner instance where on which we will
+  // execute file I/O operations.
   // All non-const methods, ctor and dtor must be called on the same thread.
   ImportantFileWriter(const FilePath& path,
-                      MessageLoopProxy* file_message_loop_proxy);
+                      base::SequencedTaskRunner* task_runner);
 
   // You have to ensure that there are no pending writes at the moment
   // of destruction.
@@ -96,8 +96,8 @@ class BASE_EXPORT ImportantFileWriter : public NonThreadSafe {
   // Path being written to.
   const FilePath path_;
 
-  // MessageLoopProxy for the thread on which file I/O can be done.
-  scoped_refptr<MessageLoopProxy> file_message_loop_proxy_;
+  // TaskRunner for the thread on which file I/O can be done.
+  const scoped_refptr<base::SequencedTaskRunner> task_runner_;
 
   // Timer used to schedule commit after ScheduleWrite.
   OneShotTimer<ImportantFileWriter> timer_;