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

chrome/browser/extensions/extension_settings_storage_unittest.cc

Index: chrome/browser/extensions/extension_settings_storage_unittest.cc
diff --git a/chrome/browser/extensions/extension_settings_storage_unittest.cc b/chrome/browser/extensions/extension_settings_storage_unittest.cc
index a36bed9c0e109d8be33c6611f65cd0ad9b45c6f2..f3080aca0dff9d6d7bef28cb79c12564cc031ff2 100644
--- a/chrome/browser/extensions/extension_settings_storage_unittest.cc
+++ b/chrome/browser/extensions/extension_settings_storage_unittest.cc
@@ -33,48 +33,86 @@ std::string ToString(const std::set<std::string>& strings) {
 
 }  // namespace
 
+// Compares two possibly NULL values for equality, filling |error| with an
+// appropriate error message if they're different.
+bool ValuesEqual(
+    const Value* expected, const Value* actual, std::string* error) {
+  if (expected == actual) {
+    return true;
+  }
+  if (expected && !actual) {
+    *error = "Expected: " + GetJSON(*expected) + ", actual: NULL";
+    return false;
+  }
+  if (actual && !expected) {
+    *error = "Expected: NULL, actual: " + GetJSON(*actual);
+    return false;
+  }
+  if (!expected->Equals(actual)) {
+    *error =
+        "Expected: " + GetJSON(*expected) + ", actual: " + GetJSON(*actual);
+    return false;
+  }
+  return true;
+}
+
 // Returns whether the result of a storage operation has the expected settings
 // and changed keys.
 testing::AssertionResult SettingsEq(
-    const char* _1, const char* _2, const char* _3,
+    const char* _1, const char* _2, const char* _3, const char* _4,
     DictionaryValue* expected_settings,
+    DictionaryValue* expected_old_settings,
     std::set<std::string>* expected_changed_keys,
     ExtensionSettingsStorage::Result actual) {
+  std::string error;
+
   if (actual.HasError()) {
     return testing::AssertionFailure() <<
         "Expected: " << GetJSON(*expected_settings) <<
         ", " << ToString(*expected_changed_keys) << "\n" <<
         ", actual has error: " << actual.GetError();
   }
-  if (expected_settings == NULL && actual.GetSettings() != NULL) {
-    return testing::AssertionFailure() <<
-        "Expected NULL settings, actual: " << GetJSON(*actual.GetSettings());
+
+  if (!ValuesEqual(expected_settings, actual.GetSettings(), &error)) {
+    return testing::AssertionFailure() << "For settings, " << error;
   }
-  if (expected_changed_keys == NULL && actual.GetChangedKeys() != NULL) {
+
+  if (!expected_changed_keys && actual.GetChangedKeys()) {
     return testing::AssertionFailure() <<
         "Expected NULL changed keys, actual: " <<
         ToString(*actual.GetChangedKeys());
   }
-  if (expected_settings != NULL && actual.GetSettings() == NULL) {
-    return testing::AssertionFailure() <<
-        "Expected: " << GetJSON(*expected_settings) << ", actual NULL";
-  }
-  if (expected_changed_keys != NULL && actual.GetChangedKeys() == NULL) {
+  if (expected_changed_keys && !actual.GetChangedKeys()) {
     return testing::AssertionFailure() <<
         "Expected: " << ToString(*expected_changed_keys) << ", actual NULL";
   }
-  if (expected_settings != actual.GetSettings() &&
-      !expected_settings->Equals(actual.GetSettings())) {
-    return testing::AssertionFailure() <<
-        "Expected: " << GetJSON(*expected_settings) <<
-        ", actual: " << GetJSON(*actual.GetSettings());
-  }
   if (expected_changed_keys != actual.GetChangedKeys() &&
         *expected_changed_keys != *actual.GetChangedKeys()) {
     return testing::AssertionFailure() <<
         "Expected: " << ToString(*expected_changed_keys) <<
         ", actual: " << ToString(*actual.GetChangedKeys());
   }
+
+  const std::set<std::string>* changed_keys = actual.GetChangedKeys();
+  if (changed_keys) {
+    for (std::set<std::string>::const_iterator it = changed_keys->begin();
+        it != changed_keys->end(); ++it) {
+      Value *expected_old_value = NULL;
+      expected_old_settings->GetWithoutPathExpansion(*it, &expected_old_value);
+      if (!ValuesEqual(expected_old_value, actual.GetOldValue(*it), &error)) {
+        return testing::AssertionFailure() << "Old values not equal: " << error;
+      }
+
+      Value *expected_new_value = NULL;
+      if (expected_settings) {
+        expected_settings->GetWithoutPathExpansion(*it, &expected_new_value);
+      }
+      if (!ValuesEqual(expected_new_value, actual.GetNewValue(*it), &error)) {
+        return testing::AssertionFailure() << "New values not equal: " << error;
+      }
+    }
+  }
+
   return testing::AssertionSuccess();
 }
 
@@ -82,10 +120,11 @@ ExtensionSettingsStorageTest::ExtensionSettingsStorageTest()
     : key1_("foo"),
       key2_("bar"),
       key3_("baz"),
-      empty_dict_(new DictionaryValue),
-      dict1_(new DictionaryValue),
-      dict12_(new DictionaryValue),
-      dict123_(new DictionaryValue),
+      empty_dict_(new DictionaryValue()),
+      dict1_(new DictionaryValue()),
+      dict3_(new DictionaryValue()),
+      dict12_(new DictionaryValue()),
+      dict123_(new DictionaryValue()),
       ui_thread_(BrowserThread::UI, MessageLoop::current()),
       file_thread_(BrowserThread::FILE, MessageLoop::current()) {
   val1_.reset(Value::CreateStringValue(key1_ + "Value"));
@@ -111,6 +150,7 @@ ExtensionSettingsStorageTest::ExtensionSettingsStorageTest()
   set123_.insert(list123_.begin(), list123_.end());
 
   dict1_->Set(key1_, val1_->DeepCopy());
+  dict3_->Set(key3_, val3_->DeepCopy());
   dict12_->Set(key1_, val1_->DeepCopy());
   dict12_->Set(key2_, val2_->DeepCopy());
   dict123_->Set(key1_, val1_->DeepCopy());
@@ -131,179 +171,179 @@ void ExtensionSettingsStorageTest::TearDown() {
 }
 
 TEST_P(ExtensionSettingsStorageTest, GetWhenEmpty) {
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(key1_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(empty_list_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(list123_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get());
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(key1_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(empty_list_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(list123_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get());
 }
 
 TEST_P(ExtensionSettingsStorageTest, GetWithSingleValue) {
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict1_.get(), &set1_, storage_->Set(key1_, *val1_));
-
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict1_.get(), NULL, storage_->Get(key1_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(key2_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(key3_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(empty_list_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict1_.get(), NULL, storage_->Get(list123_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict1_.get(), NULL, storage_->Get());
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict1_.get(), empty_dict_.get(), &set1_, storage_->Set(key1_, *val1_));
+
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict1_.get(), NULL, NULL, storage_->Get(key1_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(key2_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(key3_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(empty_list_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict1_.get(), NULL, NULL, storage_->Get(list123_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict1_.get(), NULL, NULL, storage_->Get());
 }
 
 TEST_P(ExtensionSettingsStorageTest, GetWithMultipleValues) {
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict12_.get(), &set12_, storage_->Set(*dict12_));
-
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict1_.get(), NULL, storage_->Get(key1_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(key3_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(empty_list_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict12_.get(), NULL, storage_->Get(list123_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict12_.get(), NULL, storage_->Get());
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict12_.get(), empty_dict_.get(), &set12_, storage_->Set(*dict12_));
+
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict1_.get(), NULL, NULL, storage_->Get(key1_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(key3_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(empty_list_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict12_.get(), NULL, NULL, storage_->Get(list123_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict12_.get(), NULL, NULL, storage_->Get());
 }
 
 TEST_P(ExtensionSettingsStorageTest, RemoveWhenEmpty) {
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      NULL, &empty_set_, storage_->Remove(key1_));
-
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(key1_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(list1_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get());
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      NULL, empty_dict_.get(), &empty_set_, storage_->Remove(key1_));
+
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(key1_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(list1_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get());
 }
 
 TEST_P(ExtensionSettingsStorageTest, RemoveWithSingleValue) {
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict1_.get(), &set1_, storage_->Set(*dict1_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      NULL, &set1_, storage_->Remove(key1_));
-
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(key1_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(key2_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(list1_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(list12_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get());
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict1_.get(), empty_dict_.get(), &set1_, storage_->Set(*dict1_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      NULL, dict1_.get(), &set1_, storage_->Remove(key1_));
+
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(key1_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(key2_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(list1_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(list12_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get());
 }
 
 TEST_P(ExtensionSettingsStorageTest, RemoveWithMultipleValues) {
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict123_.get(), &set123_, storage_->Set(*dict123_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      NULL, &set3_, storage_->Remove(key3_));
-
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict1_.get(), NULL, storage_->Get(key1_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(key3_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(empty_list_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict1_.get(), NULL, storage_->Get(list1_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict12_.get(), NULL, storage_->Get(list12_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict1_.get(), NULL, storage_->Get(list13_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict12_.get(), NULL, storage_->Get(list123_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict12_.get(), NULL, storage_->Get());
-
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      NULL, &set12_, storage_->Remove(list12_));
-
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(key1_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(key3_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(empty_list_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(list1_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(list12_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(list13_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(list123_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get());
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict123_.get(), empty_dict_.get(), &set123_, storage_->Set(*dict123_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      NULL, dict3_.get(), &set3_, storage_->Remove(key3_));
+
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict1_.get(), NULL, NULL, storage_->Get(key1_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(key3_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(empty_list_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict1_.get(), NULL, NULL, storage_->Get(list1_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict12_.get(), NULL, NULL, storage_->Get(list12_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict1_.get(), NULL, NULL, storage_->Get(list13_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict12_.get(), NULL, NULL, storage_->Get(list123_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict12_.get(), NULL, NULL, storage_->Get());
+
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      NULL, dict12_.get(), &set12_, storage_->Remove(list12_));
+
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(key1_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(key3_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(empty_list_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(list1_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(list12_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(list13_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(list123_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get());
 }
 
 TEST_P(ExtensionSettingsStorageTest, SetWhenOverwriting) {
   DictionaryValue key1_val2;
   key1_val2.Set(key1_, val2_->DeepCopy());
 
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      &key1_val2, &set1_, storage_->Set(key1_, *val2_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict12_.get(), &set12_, storage_->Set(*dict12_));
-
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict1_.get(), NULL, storage_->Get(key1_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(key3_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(empty_list_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict1_.get(), NULL, storage_->Get(list1_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict12_.get(), NULL, storage_->Get(list12_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict1_.get(), NULL, storage_->Get(list13_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict12_.get(), NULL, storage_->Get(list123_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict12_.get(), NULL, storage_->Get());
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      &key1_val2, empty_dict_.get(), &set1_, storage_->Set(key1_, *val2_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict12_.get(), &key1_val2, &set12_, storage_->Set(*dict12_));
+
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict1_.get(), NULL, NULL, storage_->Get(key1_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(key3_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(empty_list_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict1_.get(), NULL, NULL, storage_->Get(list1_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict12_.get(), NULL, NULL, storage_->Get(list12_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict1_.get(), NULL, NULL, storage_->Get(list13_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict12_.get(), NULL, NULL, storage_->Get(list123_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict12_.get(), NULL, NULL, storage_->Get());
 }
 
 TEST_P(ExtensionSettingsStorageTest, ClearWhenEmpty) {
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      NULL, &empty_set_, storage_->Clear());
-
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(key1_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(empty_list_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(list123_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get());
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      NULL, empty_dict_.get(), &empty_set_, storage_->Clear());
+
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(key1_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(empty_list_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(list123_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get());
 }
 
 TEST_P(ExtensionSettingsStorageTest, ClearWhenNotEmpty) {
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict12_.get(), &set12_, storage_->Set(*dict12_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      NULL, &set12_, storage_->Clear());
-
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(key1_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(empty_list_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(list123_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get());
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict12_.get(), empty_dict_.get(), &set12_, storage_->Set(*dict12_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      NULL, dict12_.get(), &set12_, storage_->Clear());
+
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(key1_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(empty_list_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(list123_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get());
 }
 
 // Dots should be allowed in key names; they shouldn't be interpreted as
@@ -318,33 +358,35 @@ TEST_P(ExtensionSettingsStorageTest, DotsInKeyNames) {
   DictionaryValue dot_dict;
   dot_dict.SetWithoutPathExpansion(dot_key, dot_value.DeepCopy());
 
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(dot_key));
-
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      &dot_dict, &dot_set, storage_->Set(dot_key, dot_value));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      &dot_dict, &empty_set_, storage_->Set(dot_key, dot_value));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      &dot_dict, NULL, storage_->Get(dot_key));
-
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      NULL, &dot_set, storage_->Remove(dot_key));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      NULL, &empty_set_, storage_->Remove(dot_key));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      &dot_dict, &dot_set, storage_->Set(dot_dict));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      &dot_dict, NULL, storage_->Get(dot_list));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      &dot_dict, NULL, storage_->Get());
-
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      NULL, &dot_set, storage_->Remove(dot_list));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get(dot_key));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get());
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(dot_key));
+
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      &dot_dict, empty_dict_.get(), &dot_set,
+      storage_->Set(dot_key, dot_value));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      &dot_dict, &dot_dict, &empty_set_,
+      storage_->Set(dot_key, dot_value));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      &dot_dict, NULL, NULL, storage_->Get(dot_key));
+
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      NULL, &dot_dict, &dot_set, storage_->Remove(dot_key));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      NULL, empty_dict_.get(), &empty_set_, storage_->Remove(dot_key));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      &dot_dict, empty_dict_.get(), &dot_set, storage_->Set(dot_dict));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      &dot_dict, NULL, NULL, storage_->Get(dot_list));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      &dot_dict, NULL, NULL, storage_->Get());
+
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      NULL, &dot_dict, &dot_set, storage_->Remove(dot_list));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get(dot_key));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get());
 }
 
 TEST_P(ExtensionSettingsStorageTest, DotsInKeyNamesWithDicts) {
@@ -355,12 +397,12 @@ TEST_P(ExtensionSettingsStorageTest, DotsInKeyNamesWithDicts) {
   std::set<std::string> changed_keys;
   changed_keys.insert("foo");
 
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      &outer_dict, &changed_keys, storage_->Set(outer_dict));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      &outer_dict, NULL, storage_->Get("foo"));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      empty_dict_.get(), NULL, storage_->Get("foo.bar"));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      &outer_dict, empty_dict_.get(), &changed_keys, storage_->Set(outer_dict));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      &outer_dict, NULL, NULL, storage_->Get("foo"));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      empty_dict_.get(), NULL, NULL, storage_->Get("foo.bar"));
 }
 
 TEST_P(ExtensionSettingsStorageTest, ComplexChangedKeysScenarios) {
@@ -371,66 +413,82 @@ TEST_P(ExtensionSettingsStorageTest, ComplexChangedKeysScenarios) {
   std::vector<std::string> complex_list;
   std::set<std::string> complex_set;
   DictionaryValue complex_dict;
+  DictionaryValue complex_changed_dict;
 
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict1_.get(), &set1_, storage_->Set(key1_, *val1_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict1_.get(), &empty_set_, storage_->Set(key1_, *val1_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict1_.get(), empty_dict_.get(), &set1_, storage_->Set(key1_, *val1_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict1_.get(), dict1_.get(), &empty_set_, storage_->Set(key1_, *val1_));
 
   complex_dict.Clear();
   complex_dict.Set(key1_, val2_->DeepCopy());
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      &complex_dict, &set1_, storage_->Set(key1_, *val2_));
-
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      NULL, &set1_, storage_->Remove(key1_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      NULL, &empty_set_, storage_->Remove(key1_));
-
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict1_.get(), &set1_, storage_->Set(key1_, *val1_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      NULL, &set1_, storage_->Clear());
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      NULL, &empty_set_, storage_->Clear());
-
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict12_.get(), &set12_, storage_->Set(*dict12_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict12_.get(), &empty_set_, storage_->Set(*dict12_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      dict123_.get(), &set3_, storage_->Set(*dict123_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      &complex_dict, dict1_.get(), &set1_, storage_->Set(key1_, *val2_));
+
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      NULL, &complex_dict, &set1_, storage_->Remove(key1_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      NULL, empty_dict_.get(), &empty_set_, storage_->Remove(key1_));
+
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict1_.get(), empty_dict_.get(), &set1_, storage_->Set(key1_, *val1_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      NULL, dict1_.get(), &set1_, storage_->Clear());
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      NULL, empty_dict_.get(), &empty_set_, storage_->Clear());
+
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict12_.get(), empty_dict_.get(), &set12_, storage_->Set(*dict12_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict12_.get(), dict12_.get(), &empty_set_, storage_->Set(*dict12_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      dict123_.get(), dict12_.get(), &set3_, storage_->Set(*dict123_));
 
   complex_dict.Clear();
   complex_dict.Set(key1_, val2_->DeepCopy());
   complex_dict.Set(key2_, val2_->DeepCopy());
   complex_dict.Set("asdf", val1_->DeepCopy());
   complex_dict.Set("qwerty", val3_->DeepCopy());
+  complex_changed_dict.Clear();
+  complex_changed_dict.Set(key1_, val1_->DeepCopy());
+  complex_changed_dict.Set(key2_, val2_->DeepCopy());
   complex_set.clear();
   complex_set.insert(key1_);
   complex_set.insert("asdf");
   complex_set.insert("qwerty");
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      &complex_dict, &complex_set, storage_->Set(complex_dict));
-
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      NULL, &set12_, storage_->Remove(list12_));
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      NULL, &empty_set_, storage_->Remove(list12_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      &complex_dict, &complex_changed_dict, &complex_set,
+      storage_->Set(complex_dict));
+
+  complex_changed_dict.Clear();
+  complex_changed_dict.Set(key1_, val2_->DeepCopy());
+  complex_changed_dict.Set(key2_, val2_->DeepCopy());
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      NULL, &complex_changed_dict, &set12_, storage_->Remove(list12_));
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      NULL, empty_dict_.get(), &empty_set_, storage_->Remove(list12_));
 
   complex_list.clear();
   complex_list.push_back(key1_);
   complex_list.push_back("asdf");
+  complex_changed_dict.Clear();
+  complex_changed_dict.Set("asdf", val1_->DeepCopy());
   complex_set.clear();
   complex_set.insert("asdf");
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      NULL, &complex_set, storage_->Remove(complex_list));
-
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      NULL,
+      &complex_changed_dict,
+      &complex_set,
+      storage_->Remove(complex_list));
+
+  complex_changed_dict.Clear();
+  complex_changed_dict.Set(key3_, val3_->DeepCopy());
+  complex_changed_dict.Set("qwerty", val3_->DeepCopy());
   complex_set.clear();
   complex_set.insert(key3_);
   complex_set.insert("qwerty");
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      NULL, &complex_set, storage_->Clear());
-  EXPECT_PRED_FORMAT3(SettingsEq,
-      NULL, &empty_set_, storage_->Clear());
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      NULL, &complex_changed_dict, &complex_set, storage_->Clear());
+  EXPECT_PRED_FORMAT4(SettingsEq,
+      NULL, empty_dict_.get(), &empty_set_, storage_->Clear());
 }