Add onChanged events to the extension settings API, both from sync and between

chrome/browser/extensions/extension_settings_sync_unittest.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "testing/gtest/include/gtest/gtest.h"
 
 #include "base/bind.h"
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop.h"
 #include "base/scoped_temp_dir.h"
 #include "base/task.h"
 #include "chrome/browser/extensions/extension_settings_backend.h"
+#include "chrome/browser/extensions/extension_settings_frontend.h"
 #include "chrome/browser/extensions/extension_settings_storage_cache.h"
 #include "chrome/browser/extensions/extension_settings_sync_util.h"
 #include "chrome/browser/extensions/syncable_extension_settings_storage.h"
 #include "chrome/browser/sync/api/sync_change_processor.h"
+#include "chrome/test/base/testing_profile.h"
 #include "content/browser/browser_thread.h"
 
 // TODO(kalman): Integration tests for sync.
 
 namespace {
 
 // Gets the pretty-printed JSON for a value.
 static std::string GetJson(const Value& value) {
   std::string json;
   base::JSONWriter::Write(&value, true, &json);
@@ skipping 67 matching lines @@
     ExtensionSettingSyncDataList matching_changes;
     for (ExtensionSettingSyncDataList::iterator it = changes_.begin();
         it != changes_.end(); ++it) {
       if (it->extension_id() == extension_id && it->key() == key) {
         matching_changes.push_back(*it);
       }
     }
     if (matching_changes.empty()) {
       ADD_FAILURE() << "No matching changes for " << extension_id << "/" <<
           key << " (out of " << changes_.size() << ")";
-      return ExtensionSettingSyncData(SyncChange::ACTION_INVALID, "", "", NULL);
+      return ExtensionSettingSyncData(
+          SyncChange::ACTION_INVALID, "", "", new DictionaryValue());
     }
     if (matching_changes.size() != 1u) {
       ADD_FAILURE() << matching_changes.size() << " matching changes for " <<
            extension_id << "/" << key << " (out of " << changes_.size() << ")";
     }
     return matching_changes[0];
   }
 
  private:
   ExtensionSettingSyncDataList changes_;
 };
 
+// To be called as a callback from ExtensionSettingsFrontend::RunWithSettings.
+void AssignSettings(
+    ExtensionSettingsBackend** dst, ExtensionSettingsBackend* src) {
+  *dst = src;
+}
+
 }  // namespace
 
 class ExtensionSettingsSyncTest : public testing::Test {
  public:
   ExtensionSettingsSyncTest()
       : ui_thread_(BrowserThread::UI, MessageLoop::current()),
-        file_thread_(BrowserThread::FILE, MessageLoop::current()) {}
+        file_thread_(BrowserThread::FILE, MessageLoop::current()),
+        frontend_(&profile_),
+        backend_(NULL) {
+  }
 
   virtual void SetUp() OVERRIDE {
-    ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
-    // TODO(kalman): Use ExtensionSettingsFrontend here?  It would test more
-    // code paths.
-    backend_.reset(new ExtensionSettingsBackend(temp_dir_.path()));
-  }
-
-  virtual void TearDown() OVERRIDE {
-    // Must do this explicitly here so that it's destroyed before the
-    // message loops are.
-    backend_.reset();
+    frontend_.RunWithBackend(base::Bind(&AssignSettings, &backend_));
+    MessageLoop::current()->RunAllPending();
+    ASSERT_TRUE(backend_ != NULL);
   }
 
  protected:
   // Creates a new extension storage object and adds a record of the extension
   // to the extension service.
   SyncableExtensionSettingsStorage* GetStorage(
       const std::string& extension_id) {
     return static_cast<SyncableExtensionSettingsStorage*>(
         backend_->GetStorage(extension_id));
   }
 
-  MockSyncChangeProcessor sync_;
-  scoped_ptr<ExtensionSettingsBackend> backend_;
-
-  // Gets all the sync data from backend_ as a map from extension id to its
+  // Gets all the sync data from |backend_| as a map from extension id to its
   // sync data.
   std::map<std::string, ExtensionSettingSyncDataList> GetAllSyncData() {
     SyncDataList as_list =
         backend_->GetAllSyncData(syncable::EXTENSION_SETTINGS);
     std::map<std::string, ExtensionSettingSyncDataList> as_map;
     for (SyncDataList::iterator it = as_list.begin();
         it != as_list.end(); ++it) {
       ExtensionSettingSyncData sync_data(*it);
       as_map[sync_data.extension_id()].push_back(sync_data);
     }
     return as_map;
   }
 
- private:
-  ScopedTempDir temp_dir_;
-
   // Need these so that the DCHECKs for running on FILE or UI threads pass.
   MessageLoop message_loop_;
   BrowserThread ui_thread_;
   BrowserThread file_thread_;
+
+  MockSyncChangeProcessor sync_;
+  TestingProfile profile_;
+  ExtensionSettingsFrontend frontend_;
+
+  // Get from frontend_->RunWithBackend, so weak reference.
+  ExtensionSettingsBackend* backend_;
 };
 
 TEST_F(ExtensionSettingsSyncTest, NoDataDoesNotInvokeSync) {
   ASSERT_EQ(0u, GetAllSyncData().size());
 
   // Have one extension created before sync is set up, the other created after.
   GetStorage("s1");
   ASSERT_EQ(0u, GetAllSyncData().size());
 
   backend_->MergeDataAndStartSyncing(
@@ skipping 301 matching lines @@
       sync_.GetOnlyChange("s3", "bar").change_type());
   ASSERT_EQ(
       SyncChange::ACTION_DELETE,
       sync_.GetOnlyChange("s4", "foo").change_type());
   ASSERT_EQ(
       SyncChange::ACTION_DELETE,
       sync_.GetOnlyChange("s4", "bar").change_type());
 
   backend_->StopSyncing(syncable::EXTENSION_SETTINGS);
 }