Basic framework for Budget API.

third_party/WebKit/Source/modules/budget/NavigatorBudget.cpp

+// Copyright 2016 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 "modules/budget/NavigatorBudget.h"
+
+#include "core/frame/Navigator.h"
+#include "modules/budget/Budget.h"
+
+namespace blink {
+
+NavigatorBudget::NavigatorBudget(Navigator* navigator)
+    : m_navigator(navigator)
+{
+}
+
+NavigatorBudget::~NavigatorBudget()
+{
+}
+
+// static
+const char* NavigatorBudget::supplementName()
+{
+    return "NavigatorBudget";
+}
+
+// static
+NavigatorBudget& NavigatorBudget::from(Navigator& navigator)
+{
+    // Get the unique NavigatorBudget associated with this navigator.
+    NavigatorBudget* navigatorBudget = static_cast<NavigatorBudget*>(Supplement<Navigator>::from(navigator, supplementName()));
+    if (!navigatorBudget) {
+        // If there has not already been a NavigatorBudget created for
+        // this navigator, create one now and associate it.

[Peter Beverloo, 2016/08/03 13:25:55]

nit: the comment on line 33/34 doesn't really add much value. I don't mind too
much either, up to you.

[harkness, 2016/08/04 14:18:23]

It's not a huge value, but I do think it makes the code more readable for a new
person. Shortened it though.

+        navigatorBudget = new NavigatorBudget(&navigator);
+        Supplement<Navigator>::provideTo(navigator, supplementName(), navigatorBudget);
+    }
+    return *navigatorBudget;
+}
+
+// static
+Budget* NavigatorBudget::budget()
+{
+    if (!m_budget)
+        m_budget = Budget::create(m_navigator);
+    return m_budget.get();
+}
+
+Budget* NavigatorBudget::budget(Navigator& navigator)
+{
+    return NavigatorBudget::from(navigator).budget();
+}
+
+DEFINE_TRACE(NavigatorBudget)
+{
+    visitor->trace(m_navigator);
+    visitor->trace(m_budget);
+    Supplement<Navigator>::trace(visitor);
+}
+
+} // namespace blink