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

third_party/WebKit/Source/platform/graphics/RecordingImageBufferSurfaceTest.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 "platform/graphics/RecordingImageBufferSurface.h"
 
 #include "platform/graphics/GraphicsContext.h"
 #include "platform/graphics/ImageBuffer.h"
 #include "platform/graphics/ImageBufferClient.h"
 #include "platform/graphics/UnacceleratedImageBufferSurface.h"
@@ skipping 246 matching lines @@
         }
 
         void postDelayedTask(const WebTraceLocation&, Task*, double delayMs) override { NOTREACHED(); };
 
         bool runsTasksOnCurrentThread() override
         {
             NOTREACHED();
             return true;
         }
 
-        WebTaskRunner* clone() override
+        std::unique_ptr<WebTaskRunner> clone() override
         {
             NOTREACHED();
             return nullptr;
         }
 
         double virtualTimeSeconds() const override
         {
             NOTREACHED();
             return 0.0;
         }
@@ skipping 113 matching lines @@
     expectDisplayListEnabled(true);
 }
 
 TEST_F(RecordingImageBufferSurfaceTest, testClearRect)
 {
     CALL_TEST_TASK_WRAPPER(testClearRect);
     expectDisplayListEnabled(true);
 }
 
 } // namespace blink