Migrate off BrowserThread::DeleteSoon in /content/browser/loader

Instead use base::DeleteSoon which enforces usage of TaskTraits.

This CL is a no-op as-is. It was recently discovered however that some
callers did BrowserThread::DeleteSoon() with pending tasks running on
different task queues (different traits  -- e.g.

TaskTraits to make this more obvious. Please review whether calls in
this CL can be migrated as-is or need additional traits to match
potentially pending tasks.

Split from https://chromium-review.googlesource.com/c/chromium/src/+/1894109
for cursory review.

This CL was uploaded by git cl split.

R=yhirano@chromium.org


TaskPriority: :BEST_EFFORT) which can result in out-of-order deletion...
BrowserThread: :DeleteSoon() is being migrated to base::DeleteSoon() w/
Bug: 1019767
Change-Id: I73d70979b1b3e1545de81963d2082652872f4f31
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1893541
Auto-Submit: Gabriel Charette <gab@chromium.org>
Reviewed-by: Yutaka Hirano <yhirano@chromium.org>
Commit-Queue: Gabriel Charette <gab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#711783}

content/browser/loader/cross_origin_read_blocking_checker.cc

@@ -127,8 +127,7 @@ CrossOriginReadBlockingChecker::CrossOriginReadBlockingChecker(
 }
 
 CrossOriginReadBlockingChecker::~CrossOriginReadBlockingChecker() {
-  BrowserThread::DeleteSoon(BrowserThread::IO, FROM_HERE,
-                            std::move(blob_io_state_));
+  base::DeleteSoon(FROM_HERE, {BrowserThread::IO}, std::move(blob_io_state_));
 }
 
 int CrossOriginReadBlockingChecker::GetNetError() {