Have CanvasAsyncBlobCreator's delayed task keep a weak |this| also.

third_party/WebKit/Source/core/html/canvas/CanvasAsyncBlobCreator.cpp

 // Copyright 2015 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/html/canvas/CanvasAsyncBlobCreator.h"
 
 #include "core/fileapi/Blob.h"
 #include "platform/ThreadSafeFunctional.h"
 #include "platform/graphics/ImageBuffer.h"
 #include "platform/image-encoders/JPEGImageEncoder.h"
@@ skipping 100 matching lines @@
         } else if (m_mimeType == MimeTypeJpeg) {
             this->scheduleInitiateJpegEncoding(quality);
         } else {
             // Progressive encoding is only applicable to png and jpeg image format,
             // and thus idle tasks scheduling can only be applied to these image formats.
             // TODO(xlai): Progressive encoding on webp image formats (crbug.com/571399)
             ASSERT_NOT_REACHED();
         }
         // We post the below task to check if the above idle task isn't late.
         // There's no risk of concurrency as both tasks are on main thread.
-        this->postDelayedTaskToMainThread(BLINK_FROM_HERE, bind(&CanvasAsyncBlobCreator::idleTaskStartTimeoutEvent, this, quality), IdleTaskStartTimeoutDelay);
+        this->postDelayedTaskToMainThread(BLINK_FROM_HERE, bind(&CanvasAsyncBlobCreator::idleTaskStartTimeoutEvent, WeakPersistentThisPointer<CanvasAsyncBlobCreator>(this), quality), IdleTaskStartTimeoutDelay);
     } else if (m_mimeType == MimeTypeWebp) {
         BackgroundTaskRunner::TaskSize taskSize = (m_size.height() * m_size.width() >= LongTaskImageSizeThreshold) ? BackgroundTaskRunner::TaskSizeLongRunningTask : BackgroundTaskRunner::TaskSizeShortRunningTask;
         BackgroundTaskRunner::postOnBackgroundThread(BLINK_FROM_HERE, threadSafeBind(&CanvasAsyncBlobCreator::encodeImageOnEncoderThread, wrapCrossThreadPersistent(this), quality), taskSize);
     }
 }
 
 void CanvasAsyncBlobCreator::scheduleInitiateJpegEncoding(const double& quality)
 {
     Platform::current()->mainThread()->scheduler()->postIdleTask(BLINK_FROM_HERE, bind<double>(&CanvasAsyncBlobCreator::initiateJpegEncoding, WeakPersistentThisPointer<CanvasAsyncBlobCreator>(this), quality));
 }
@@ skipping 221 matching lines @@
     }
 }
 
 void CanvasAsyncBlobCreator::postDelayedTaskToMainThread(const WebTraceLocation& location, std::unique_ptr<SameThreadClosure> task, double delayMs)
 {
     DCHECK(isMainThread());
     Platform::current()->mainThread()->getWebTaskRunner()->postDelayedTask(location, std::move(task), delayMs);
 }
 
 } // namespace blink