Regression Information
First Bad Build: https://uberchromegw.corp.google.com/i/official.desktop/builders/linux64/builds/616
Last Good Build: https://uberchromegw.corp.google.com/i/official.desktop/builders/linux64/builds/612

Error Log Link:
===============
https://luci-logdog.appspot.com/v/?s=chrome%2Fbb%2Fofficial.desktop%2Flinux64%2F616%2F%2B%2Frecipes%2Fsteps%2Fbrowser_tests%2F0%2Fstdout#

Error Log:
===========
[15127:15233:0920/223212.150533:WARNING:embedded_test_server.cc(229)] Request not handled. Returning 404: /favicon.ico
../../chrome/browser/profiling_host/memlog_browsertest.cc:89: Failure
Value of: found_browser_alloc
  Actual: false
Expected: true
Failed to find an allocation of the appropriate size. Did the send buffer not flush? (size: 216006656 count:2048)
Google Test trace:
../../chrome/browser/profiling_host/memlog_browsertest.cc:216: Validating Browser Allocation
../../chrome/browser/profiling_host/memlog_browsertest.cc:226: Failure
Expected: ValidateDump(dump_json.get(), kBrowserAllocSize * kBrowserAllocCount, kBrowserAllocCount) doesn't generate new fatal failures in the current thread.
  Actual: it does.
Google Test trace:
../../chrome/browser/profiling_host/memlog_browsertest.cc:216: Validating Browser Allocation
[15127:15127:0920/223212.381197:INFO:chrome_cryptauth_service.cc(222)] Profile is not authenticated yet; waiting before starting CryptAuth managers.
[  FAILED  ] BrowserOnly/MemlogBrowserTest.EndToEnd/0, where GetParam() = "minimal" (1388 ms)
[6918/6918] BrowserOnly/MemlogBrowserTest.EndToEnd/0 (1572 ms)
2 tests failed:
    AllProcesses/MemlogBrowserTest.EndToEnd/0 (../../chrome/browser/profiling_host/memlog_browsertest.cc:150)
    BrowserOnly/MemlogBrowserTest.EndToEnd/0 (../../chrome/browser/profiling_host/memlog_browsertest.cc:150)
<Thread(Thread-1, started 140171987191552)> ProcessRead: proc.stdout finished.
<Thread(Thread-1, started 140171987191552)> ProcessRead: cleaning up.
<Thread(Thread-2, started daemon 140171978798848)> TimedFlush: Finished
<Thread(Thread-1, started 140171987191552)> ProcessRead: finished.

etienneb@, can you please look into this change (https://chromium.googlesource.com/chromium/src/+/6081ba4689b78d110f637cad0bb29d25fd09e771) if possible?

Here is the Change Log: https://chromium.googlesource.com/chromium/src/+log/63.0.3220.0..63.0.3221.0?pretty=fuller&n=10000

These tests are failing from 20th Sep 2017, so would be great if we fix this issue ASAP.

Thank you!