Support IPH NotifyEvent calls before Initialize

components/feature_engagement_tracker/internal/init_aware_model.cc

Index: components/feature_engagement_tracker/internal/init_aware_model.cc
diff --git a/components/feature_engagement_tracker/internal/init_aware_model.cc b/components/feature_engagement_tracker/internal/init_aware_model.cc
new file mode 100644
index 0000000000000000000000000000000000000000..a5ab190af9fcf850527ec3227b602bf463bb675d
--- /dev/null
+++ b/components/feature_engagement_tracker/internal/init_aware_model.cc
@@ -0,0 +1,55 @@
+// Copyright 2017 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 "components/feature_engagement_tracker/internal/init_aware_model.h"
+
+#include "base/bind.h"
+
+namespace feature_engagement_tracker {
+
+InitAwareModel::InitAwareModel(std::unique_ptr<Model> model)
+    : model_(std::move(model)), weak_ptr_factory_(this) {
+  DCHECK(model_);
+}
+
+InitAwareModel::~InitAwareModel() = default;
+
+void InitAwareModel::Initialize(const OnModelInitializationFinished& callback,
+                                uint32_t current_day) {
+  model_->Initialize(base::Bind(&InitAwareModel::OnInitializeComplete,
+                                weak_ptr_factory_.GetWeakPtr(), callback),
+                     current_day);
+}
+
+bool InitAwareModel::IsReady() const {
+  return model_->IsReady();
+}
+
+const Event* InitAwareModel::GetEvent(const std::string& event_name) const {
+  return model_->GetEvent(event_name);
+}
+
+void InitAwareModel::IncrementEvent(const std::string& event_name,
+                                    uint32_t current_day) {
+  if (IsReady()) {
+    model_->IncrementEvent(event_name, current_day);
+    return;
+  }
+
+  queued_events_.push_back(std::tie(event_name, current_day));
+}
+
+void InitAwareModel::OnInitializeComplete(
+    const OnModelInitializationFinished& callback,
+    bool success) {
+  if (success) {
+    for (auto& event : queued_events_)
+      model_->IncrementEvent(std::get<0>(event), std::get<1>(event));
+    queued_events_.clear();
+  }
+
+  callback.Run(success);
+}
+
+}  // namespace feature_engagement_tracker