The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/03ec7e3dd354a3cc0d3357c14ecc21e1085bbbaa

commit 03ec7e3dd354a3cc0d3357c14ecc21e1085bbbaa
Author: jri <jri@chromium.org>
Date: Tue Sep 13 20:13:56 2016

Disables QUIC flag that shifts cubic epoch on quiescence, since shifting code is buggy and should not be used.

BUG= 646495 

Review-Url: https://codereview.chromium.org/2336253003
Cr-Commit-Position: refs/heads/master@{#418348}

[modify] https://crrev.com/03ec7e3dd354a3cc0d3357c14ecc21e1085bbbaa/net/quic/core/quic_flags_list.h

Approving merge to M53 branch 2785 based on our group chat. Please merge ASAP. Thank you.

Issue 646557 has been merged into this issue.

Based on discussion this is high priority and an isolated change, so approving for M54 without letting it bake in canary.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c662f05a6aba644548300499c7a3c76b7da5fc46

commit c662f05a6aba644548300499c7a3c76b7da5fc46
Author: Jana Iyengar <jri@chromium.org>
Date: Tue Sep 13 21:47:00 2016

[M53 merge] Disables QUIC flag that shifts cubic epoch on quiescence, since shifting code is buggy and should not be used.

R=rch@chromium.org
BUG= 646495 

Review URL: https://codereview.chromium.org/2341513002 .

Cr-Commit-Position: refs/branch-heads/2785@{#884}
Cr-Branched-From: 68623971be0cfc492a2cb0427d7f478e7b214c24-refs/heads/master@{#403382}

[modify] https://crrev.com/c662f05a6aba644548300499c7a3c76b7da5fc46/net/quic/quic_flags.cc

I don't think there's a reason to keep this bug restricted.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a924edb808ec6d88031f4246c546ca8081e40dca

commit a924edb808ec6d88031f4246c546ca8081e40dca
Author: Jana Iyengar <jri@chromium.org>
Date: Tue Sep 13 22:16:33 2016

[M54 merge] Disables QUIC flag that shifts cubic epoch on quiescence, since shifting code is buggy and should not be used.

R=rch@chromium.org
BUG= 646495 

Review URL: https://codereview.chromium.org/2335393002 .

Cr-Commit-Position: refs/branch-heads/2840@{#344}
Cr-Branched-From: 1ae106dbab4bddd85132d5b75c670794311f4c57-refs/heads/master@{#414607}

[modify] https://crrev.com/a924edb808ec6d88031f4246c546ca8081e40dca/net/quic/core/quic_flags.cc

Verified the fix on latest Chrome M53 i.e., 53.0.2785.116 and 54.0.2840.27 on Windows and Mac with lower bandwidth network and the packet lost was ~3%, But the same before the fix packet lost was around ~65%.

Steps Followed :
1. Install Chrome M53 or M54(version numbers as mentioned above)
2. Sign in to Google drive and try to upload a large file(in my testing I used file size of 5Gb)
3. Open "chrome://net-internals/#quic and lookout for the packet lot rate for the drive.google.com

Observed behavior :
The packet lost is ~3% of the file size

oop's forgot to mention : 

Stable QUIC version : 34 
Beta QUIC version : 35

Thanks for verifying, pbommana!

Verified fix on 53.0.2785.121 build on 2G network. 671/10857 packets lost.

Marking as fixed and verified.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a924edb808ec6d88031f4246c546ca8081e40dca

commit a924edb808ec6d88031f4246c546ca8081e40dca
Author: Jana Iyengar <jri@chromium.org>
Date: Tue Sep 13 22:16:33 2016

[M54 merge] Disables QUIC flag that shifts cubic epoch on quiescence, since shifting code is buggy and should not be used.

R=rch@chromium.org
BUG= 646495 

Review URL: https://codereview.chromium.org/2335393002 .

Cr-Commit-Position: refs/branch-heads/2840@{#344}
Cr-Branched-From: 1ae106dbab4bddd85132d5b75c670794311f4c57-refs/heads/master@{#414607}

[modify] https://crrev.com/a924edb808ec6d88031f4246c546ca8081e40dca/net/quic/core/quic_flags.cc