The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/2e3335cba62f8affac406dd45f5c9138775386a5

commit 2e3335cba62f8affac406dd45f5c9138775386a5
Author: Marijn Kruisselbrink <mek@chromium.org>
Date: Tue Jul 03 21:31:20 2018

Rewrite BlobBytesConsumer to not rely on blob URLs.

The existing implementation depended on the non-mojo blob URL code path,
and so would break soon after mojo blob URLs ship when the old code gets
deleted. So rewrite the implementation to read blobs more directly rather
than going through a blob URL.

Bug:  859109 
Change-Id: Ia6f2432e48ac5304ea8f5598d293e31c2c1e1905
Reviewed-on: https://chromium-review.googlesource.com/1120679
Commit-Queue: Marijn Kruisselbrink <mek@chromium.org>
Reviewed-by: Yutaka Hirano <yhirano@chromium.org>
Cr-Commit-Position: refs/heads/master@{#572363}
[modify] https://crrev.com/2e3335cba62f8affac406dd45f5c9138775386a5/third_party/WebKit/LayoutTests/external/wpt/fetch/api/response/response-cancel-stream.html
[modify] https://crrev.com/2e3335cba62f8affac406dd45f5c9138775386a5/third_party/blink/renderer/core/fetch/blob_bytes_consumer.cc
[modify] https://crrev.com/2e3335cba62f8affac406dd45f5c9138775386a5/third_party/blink/renderer/core/fetch/blob_bytes_consumer.h
[modify] https://crrev.com/2e3335cba62f8affac406dd45f5c9138775386a5/third_party/blink/renderer/core/fetch/blob_bytes_consumer_test.cc
[modify] https://crrev.com/2e3335cba62f8affac406dd45f5c9138775386a5/third_party/blink/renderer/core/fetch/form_data_bytes_consumer.cc
[modify] https://crrev.com/2e3335cba62f8affac406dd45f5c9138775386a5/third_party/blink/renderer/platform/blob/blob_data.cc
[modify] https://crrev.com/2e3335cba62f8affac406dd45f5c9138775386a5/third_party/blink/renderer/platform/blob/blob_data.h
[modify] https://crrev.com/2e3335cba62f8affac406dd45f5c9138775386a5/third_party/blink/renderer/platform/blob/blob_registry.h
[modify] https://crrev.com/2e3335cba62f8affac406dd45f5c9138775386a5/third_party/blink/renderer/platform/blob/testing/fake_blob.cc
[modify] https://crrev.com/2e3335cba62f8affac406dd45f5c9138775386a5/third_party/blink/renderer/platform/blob/testing/fake_blob.h