Moved JsonPrefStore to use SequencedWorkerPool

chrome/browser/extensions/test_extension_prefs.h

Index: chrome/browser/extensions/test_extension_prefs.h
diff --git a/chrome/browser/extensions/test_extension_prefs.h b/chrome/browser/extensions/test_extension_prefs.h
index 5fb1ec557e36a8f94cbee86267709e447517449c..485a15b5105cffd024f7b12e7d17745ba68de23c 100644
--- a/chrome/browser/extensions/test_extension_prefs.h
+++ b/chrome/browser/extensions/test_extension_prefs.h
@@ -8,6 +8,7 @@
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
+#include "base/message_loop.h"
 #include "base/scoped_temp_dir.h"
 #include "chrome/common/extensions/extension.h"
 
@@ -16,6 +17,7 @@ class PrefService;
 
 namespace base {
 class DictionaryValue;
+class SequencedWorkerPool;
 }
 
 namespace extensions {
@@ -25,7 +27,7 @@ class ExtensionPrefs;
 // in tests.
 class TestExtensionPrefs {
  public:
-  TestExtensionPrefs();
+  TestExtensionPrefs(base::SequencedWorkerPool* blocking_pool);
   virtual ~TestExtensionPrefs();
 
   ExtensionPrefs* prefs() { return prefs_.get(); }
@@ -76,6 +78,8 @@ class TestExtensionPrefs {
   scoped_ptr<PrefService> pref_service_;
   scoped_ptr<ExtensionPrefs> prefs_;
   scoped_ptr<ExtensionPrefValueMap> extension_pref_value_map_;
+  // A blocking pool that we can use for file operations.
+  scoped_refptr<base::SequencedWorkerPool> blocking_pool_;
 
  private:
   bool extensions_disabled_;