Use std::unique_ptr<> for WebTaskRunner::clone

third_party/WebKit/Source/core/layout/ImageQualityControllerTest.cpp

 // Copyright 2014 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/layout/ImageQualityController.h"
 
 #include "core/layout/LayoutImage.h"
 #include "core/layout/LayoutTestHelper.h"
 #include "platform/graphics/GraphicsContext.h"
 #include "platform/graphics/paint/PaintController.h"
@@ skipping 115 matching lines @@
 private:
     void postTask(const WebTraceLocation&, Task*) override { }
     void postDelayedTask(const WebTraceLocation&, Task* task, double) override
     {
         if (m_currentTask)
             delete m_currentTask;
         m_currentTask = task;
 
     }
     bool runsTasksOnCurrentThread() override { return true; }
-    WebTaskRunner* clone() override { return nullptr; }
+    std::unique_ptr<WebTaskRunner> clone() override { return nullptr; }
     double virtualTimeSeconds() const override { return 0.0; }
     double monotonicallyIncreasingVirtualTimeSeconds() const override { return m_time; }
 
     double m_time;
     Task* m_currentTask;
 };
 
 class MockTimer : public Timer<ImageQualityController> {
     typedef void (ImageQualityController::*TimerFiredFunction)(Timer*);
 public:
@@ skipping 122 matching lines @@
     // This animation is far enough in the future to make the timer restart, since it is half over.
     nextTime = 0.1 + ImageQualityController::cTimerRestartThreshold + 0.01;
     EXPECT_EQ(true, controller()->shouldPaintAtLowQuality(*img, testImage.get(), testImage.get(), LayoutSize(4, 4), nextTime));
     // Now the timer has restarted, leading to a larger fire interval.
     EXPECT_EQ(ImageQualityController::cLowQualityTimeThreshold, mockTimer->nextFireInterval());
 }
 
 #endif
 
 } // namespace blink