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

chrome/browser/extensions/extension_settings_sync_unittest.cc

Index: chrome/browser/extensions/extension_settings_sync_unittest.cc
diff --git a/chrome/browser/extensions/extension_settings_sync_unittest.cc b/chrome/browser/extensions/extension_settings_sync_unittest.cc
index f9b34f962f1d0ade39f4417df68917390f90428c..70734751c8fd71d3de9852dfff6e0c68f04e1608 100644
--- a/chrome/browser/extensions/extension_settings_sync_unittest.cc
+++ b/chrome/browser/extensions/extension_settings_sync_unittest.cc
@@ -12,10 +12,12 @@
 #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.
@@ -103,7 +105,8 @@ class MockSyncChangeProcessor : public SyncChangeProcessor {
     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 " <<
@@ -116,25 +119,27 @@ class MockSyncChangeProcessor : public SyncChangeProcessor {
   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()) {}
-
-  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()));
+        file_thread_(BrowserThread::FILE, MessageLoop::current()),
+        frontend_(&profile_),
+        backend_(NULL) {
   }
 
-  virtual void TearDown() OVERRIDE {
-    // Must do this explicitly here so that it's destroyed before the
-    // message loops are.
-    backend_.reset();
+  virtual void SetUp() OVERRIDE {
+    frontend_.RunWithBackend(base::Bind(&AssignSettings, &backend_));
+    MessageLoop::current()->RunAllPending();
+    ASSERT_TRUE(backend_ != NULL);
   }
 
  protected:
@@ -146,10 +151,7 @@ class ExtensionSettingsSyncTest : public testing::Test {
         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 =
@@ -163,13 +165,17 @@ class ExtensionSettingsSyncTest : public testing::Test {
     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) {