Moved JsonPrefStore to use SequencedWorkerPool

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 735cba8acb25dc9e8cff36bb2870cc7a987155a7..d165de12d6a9cf8d1cd2b67ba07c21cba695a1e3 100644
--- a/chrome/browser/profiles/profile_impl.cc
+++ b/chrome/browser/profiles/profile_impl.cc
@@ -16,6 +16,7 @@
 #include "base/string_tokenizer.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
+#include "base/threading/sequenced_worker_pool.h"
 #include "base/utf_string_conversions.h"
 #include "base/version.h"
 #include "chrome/browser/autocomplete/autocomplete_classifier.h"
@@ -208,12 +209,22 @@ std::string ExitTypeToSessionTypePrefValue(Profile::ExitType type) {
 Profile* Profile::CreateProfile(const FilePath& path,
                                 Delegate* delegate,
                                 CreateMode create_mode) {
+  // Get sequenced task runner for making sure that file operations of
+  // this profile (defined by |path|) are executed in expected order
+  // (what was previously assured by the FILE thread).
+  scoped_refptr<base::SequencedTaskRunner> sequenced_task_runner =
+      BrowserThread::GetBlockingPool()->
+        GetSequencedTaskRunnerWithShutdownBehavior(
+            BrowserThread::GetBlockingPool()->GetNamedSequenceToken(
+                path.AsUTF8Unsafe()),
+            base::SequencedWorkerPool::BLOCK_SHUTDOWN);
   if (create_mode == CREATE_MODE_ASYNCHRONOUS) {
     DCHECK(delegate);
-    // This is safe while all file operations are done on the FILE thread.
-    BrowserThread::PostTask(
-        BrowserThread::FILE, FROM_HERE,
-        base::Bind(&CreateDirectoryNoResult, path));
+    // We need to make sure that profile directory is created on the same
+    // blocking pool where we will run all its important file serialization
+    // tasks (i.e. JsonPrefStore).
+    sequenced_task_runner->PostTask(FROM_HERE,
+                                    base::Bind(&CreateDirectoryNoResult, path));
   } else if (create_mode == CREATE_MODE_SYNCHRONOUS) {
     if (!file_util::PathExists(path)) {
       // TODO(tc): http://b/1094718 Bad things happen if we can't write to the
@@ -226,7 +237,7 @@ Profile* Profile::CreateProfile(const FilePath& path,
     NOTREACHED();
   }
 
-  return new ProfileImpl(path, delegate, create_mode);
+  return new ProfileImpl(path, delegate, create_mode, sequenced_task_runner);
 }
 
 // static
@@ -279,9 +290,11 @@ void ProfileImpl::RegisterUserPrefs(PrefService* prefs) {
                              PrefService::SYNCABLE_PREF);
 }
 
-ProfileImpl::ProfileImpl(const FilePath& path,
-                         Delegate* delegate,
-                         CreateMode create_mode)
+ProfileImpl::ProfileImpl(
+    const FilePath& path,
+    Delegate* delegate,
+    CreateMode create_mode,
+    scoped_refptr<base::SequencedTaskRunner> sequenced_task_runner)
     : path_(path),
       ALLOW_THIS_IN_INITIALIZER_LIST(visited_link_event_listener_(
           new VisitedLinkEventListener(this))),
@@ -331,7 +344,8 @@ ProfileImpl::ProfileImpl(const FilePath& path,
         policy_service_.get(),
         new ExtensionPrefStore(
             ExtensionPrefValueMapFactory::GetForProfile(this), false),
-        true));
+        true,
+        sequenced_task_runner));
     // Wait for the notification that prefs has been loaded (successfully or
     // not).
     registrar_.Add(this, chrome::NOTIFICATION_PREF_INITIALIZATION_COMPLETED,
@@ -343,7 +357,8 @@ ProfileImpl::ProfileImpl(const FilePath& path,
         policy_service_.get(),
         new ExtensionPrefStore(
             ExtensionPrefValueMapFactory::GetForProfile(this), false),
-        false));
+        false,
+        sequenced_task_runner));
     OnPrefsLoaded(true);
   } else {
     NOTREACHED();