Adds async interface method to PersistentPrefStore.

chrome/common/json_pref_store_unittest.cc

Index: chrome/common/json_pref_store_unittest.cc
diff --git a/chrome/common/json_pref_store_unittest.cc b/chrome/common/json_pref_store_unittest.cc
index e7f34f520331b8fb37e80bd874a1874da1ae3da0..4ee5abb00378b8522a7ee5053709b110439f41d6 100644
--- a/chrome/common/json_pref_store_unittest.cc
+++ b/chrome/common/json_pref_store_unittest.cc
@@ -5,6 +5,7 @@
 #include "base/file_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/scoped_temp_dir.h"
 #include "base/message_loop.h"
 #include "base/message_loop_proxy.h"
 #include "base/path_service.h"
@@ -13,12 +14,22 @@
 #include "base/threading/thread.h"
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
-#include "base/memory/scoped_temp_dir.h"
-#include "chrome/common/json_pref_store.h"
 #include "chrome/common/chrome_paths.h"
+#include "chrome/common/json_pref_store.h"
 #include "chrome/common/pref_names.h"
+#include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+namespace {
+
+class MockPrefStoreObserver: public PrefStore::Observer {
+ public:
+  MOCK_METHOD1(OnPrefValueChanged, void (const std::string&));
+  MOCK_METHOD0(OnInitializationCompleted, void ());
+};
+
+}  // namespace
+
 class JsonPrefStoreTest : public testing::Test {
  protected:
   virtual void SetUp() {
@@ -160,3 +171,31 @@ TEST_F(JsonPrefStoreTest, Basic) {
   EXPECT_TRUE(file_util::TextContentsEqual(golden_output_file, output_file));
   ASSERT_TRUE(file_util::Delete(output_file, false));
 }
+
+// Tests asynchronous reading of the file when there is no file.
+TEST_F(JsonPrefStoreTest, AsyncNonExistingFile) {
+  FilePath bogus_input_file = data_dir_.AppendASCII("read.txt");
+  ASSERT_FALSE(file_util::PathExists(bogus_input_file));
+  scoped_refptr<JsonPrefStore> pref_store =
+      new JsonPrefStore(bogus_input_file, message_loop_proxy_.get());
+  MockPrefStoreObserver mock_observer;
+  pref_store->AddObserver(&mock_observer);
+
+  PersistentPrefStore::PrefReadError error;
+  bool is_fatal;
+  pref_store->GetErrors(&error, &is_fatal);
+  EXPECT_EQ(PersistentPrefStore::PREF_READ_ERROR_NONE, error);
+  EXPECT_FALSE(is_fatal);
+
+  pref_store->ReadPrefsAsync();
+
+  EXPECT_CALL(mock_observer, OnInitializationCompleted()).Times(1);
+  message_loop_.RunAllPending();
+  pref_store->RemoveObserver(&mock_observer);
+
+  pref_store->GetErrors(&error, &is_fatal);
+
+  EXPECT_EQ(PersistentPrefStore::PREF_READ_ERROR_NO_FILE, error);
+  EXPECT_FALSE(is_fatal);
+  EXPECT_FALSE(pref_store->ReadOnly());
+}