The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ad2949ac9cb3919d1f3866f10dd2e03cc1856e2a

commit ad2949ac9cb3919d1f3866f10dd2e03cc1856e2a
Author: Evan Stade <estade@chromium.org>
Date: Fri Aug 11 17:44:17 2017

Count a WebContents as "no longer waiting for response" after receiving
a DidGetResourceResponseStart callback.

Bug:  752326 
Change-Id: I27c8eb9a26dccd5d5578aa34d575eb4bd46d0f24
Reviewed-on: https://chromium-review.googlesource.com/601254
Reviewed-by: Charlie Reis <creis@chromium.org>
Commit-Queue: Evan Stade <estade@chromium.org>
Cr-Commit-Position: refs/heads/master@{#493789}
[modify] https://crrev.com/ad2949ac9cb3919d1f3866f10dd2e03cc1856e2a/content/browser/web_contents/web_contents_impl.cc
[modify] https://crrev.com/ad2949ac9cb3919d1f3866f10dd2e03cc1856e2a/content/browser/web_contents/web_contents_impl_browsertest.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/68ea89401ba9c4c8fcc0070c356d443be95e20e0

commit 68ea89401ba9c4c8fcc0070c356d443be95e20e0
Author: Evan Stade <estade@chromium.org>
Date: Thu Aug 17 22:31:30 2017

Revert "Count a WebContents as "no longer waiting for response" after receiving"

This reverts commit ad2949ac9cb3919d1f3866f10dd2e03cc1856e2a.

Reason for revert: suspect for perf regression:  crbug.com/755182 

Original change's description:
> Count a WebContents as "no longer waiting for response" after receiving
> a DidGetResourceResponseStart callback.
> 
> Bug:  752326 
> Change-Id: I27c8eb9a26dccd5d5578aa34d575eb4bd46d0f24
> Reviewed-on: https://chromium-review.googlesource.com/601254
> Reviewed-by: Charlie Reis <creis@chromium.org>
> Commit-Queue: Evan Stade <estade@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#493789}

TBR=avi@chromium.org,creis@chromium.org,jam@chromium.org,estade@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug:  752326 
Change-Id: I8ac5805abf516384e8a27d5166bf1fee45be366f
Reviewed-on: https://chromium-review.googlesource.com/619766
Reviewed-by: Evan Stade <estade@chromium.org>
Commit-Queue: Evan Stade <estade@chromium.org>
Cr-Commit-Position: refs/heads/master@{#495355}
[modify] https://crrev.com/68ea89401ba9c4c8fcc0070c356d443be95e20e0/content/browser/web_contents/web_contents_impl.cc
[modify] https://crrev.com/68ea89401ba9c4c8fcc0070c356d443be95e20e0/content/browser/web_contents/web_contents_impl_browsertest.cc

The revert did fix the perf regression, although why is still a mystery to me and with the revert I can once again repro the bug (backwards spinning throbber after content has already begun loading).

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/38e4aee64eccdaeff1b9b8010b574d047693bbbe

commit 38e4aee64eccdaeff1b9b8010b574d047693bbbe
Author: Evan Stade <estade@chromium.org>
Date: Wed Aug 23 17:06:18 2017

Re-land ad2949ac9cb3919d1f3866f1 - Count a WebContents as "no longer
waiting for response" after receiving a DidGetResourceResponseStart
callback.

Skia memory regression on Windows is incidental (due to loading more of
Segoe UI into memory).

TBR=creis@chromium.org

Bug:  752326 
Change-Id: I0e01331b8299ead239e9b1dc829fbe8810d92ced
Reviewed-on: https://chromium-review.googlesource.com/627043
Reviewed-by: Evan Stade <estade@chromium.org>
Commit-Queue: Evan Stade <estade@chromium.org>
Cr-Commit-Position: refs/heads/master@{#496718}
[modify] https://crrev.com/38e4aee64eccdaeff1b9b8010b574d047693bbbe/content/browser/web_contents/web_contents_impl.cc
[modify] https://crrev.com/38e4aee64eccdaeff1b9b8010b574d047693bbbe/content/browser/web_contents/web_contents_impl_browsertest.cc