requestIdleCallback: Yield for high priority work

third_party/WebKit/Source/core/dom/IdleDeadlineTest.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 "core/dom/IdleDeadline.h"
+
+#include "platform/testing/TestingPlatformSupport.h"
+#include "public/platform/Platform.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "wtf/CurrentTime.h"
+
+namespace blink {
+namespace {
+
+class MockScheduler final : public TestingPlatformMockScheduler {
+ public:
+  MockScheduler() {}
+  ~MockScheduler() override {}
+  bool shouldYieldForHighPriorityWork() override { return true; }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(MockScheduler);
+};
+
+class MockThread final : public WebThread {
+ public:
+  MockThread() {}
+  ~MockThread() override {}
+  bool isCurrentThread() const override { return true; }
+  WebScheduler* scheduler() const override { return &m_scheduler; }
+
+ private:
+  mutable MockScheduler m_scheduler;
+  DISALLOW_COPY_AND_ASSIGN(MockThread);
+};
+
+class MockPlatform : public TestingPlatformSupport {
+ public:
+  MockPlatform() {}
+  ~MockPlatform() override {}
+  WebThread* currentThread() override { return &m_thread; }
+
+ private:
+  MockThread m_thread;
+  DISALLOW_COPY_AND_ASSIGN(MockPlatform);
+};
+
+}  // namespace
+
+TEST(IdleDeadline, deadlineInFuture) {
+  setTimeFunctionsForTesting([] { return 1.0; });
+  IdleDeadline* deadline =
+      IdleDeadline::create(1.25, IdleDeadline::CallbackType::CalledWhenIdle);
+  // Note: the deadline is computed with reduced resolution.
+  EXPECT_FLOAT_EQ(249.995, deadline->timeRemaining());
+}
+
+TEST(IdleDeadline, deadlineInPast) {
+  setTimeFunctionsForTesting([] { return 1.0; });
+  IdleDeadline* deadline =
+      IdleDeadline::create(0.75, IdleDeadline::CallbackType::CalledWhenIdle);
+  EXPECT_FLOAT_EQ(0, deadline->timeRemaining());
+}
+
+TEST(IdleDeadline, yieldForHighPriorityWork) {
+  MockPlatform platform;
+
+  setTimeFunctionsForTesting([] { return 1.0; });
+  IdleDeadline* deadline =
+      IdleDeadline::create(1.25, IdleDeadline::CallbackType::CalledWhenIdle);
+  EXPECT_FLOAT_EQ(0, deadline->timeRemaining());
+}
+
+}  // namespace blink