Block mixed PingLoader requests.

Block mixed PingLoader requests.

We should block HTTP requests in an HTTPS context whenever possible.
Pings are practically zero-impact to users, so blocking them via a mixed
content warning is very low risk.

Mozilla is making the same change: https://hg.mozilla.org/try/rev/5a9f4d5a8707

BUG=382798
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=176681

[Mike West, 2014-06-10 12:21:47]

WDYT, Tom?

-mike

[Tom Sepez, 2014-06-10 18:12:46]

On 2014/06/10 12:21:47, Mike West wrote:
> WDYT, Tom?
> 
> -mike
Can we separate the de-flake into its own CL? It would be a shame to lose that
when down the road, we hit the one site somewhere that can't live with the new
behaviour and this gets reverted ...

[Mike West, 2014-06-10 18:50:05]

On 2014/06/10 at 18:12:46, tsepez wrote:
> On 2014/06/10 12:21:47, Mike West wrote:
> > WDYT, Tom?
> > 
> > -mike
> Can we separate the de-flake into its own CL? It would be a shame to lose that
when down the road, we hit the one site somewhere that can't live with the new
behaviour and this gets reverted ...

Cynic. :)

But yeah, I'll split that bit out in the morning. No problem.

[Mike West, 2014-06-20 14:54:03]

Mind taking another look, Tom? I landed the deflake portion a few days ago...

-mike

[Tom Sepez, 2014-06-20 22:14:16]

lgtm

[Mike West, 2014-06-21 03:22:58]

The CQ bit was checked by mkwst@chromium.org

[commit-bot: I haz the power, 2014-06-21 03:24:07]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mkwst@chromium.org/324013003/40001

[commit-bot: I haz the power, 2014-06-21 04:26:43]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  win_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/win_blink_rel/builds/13020)

[commit-bot: I haz the power, 2014-06-21 04:38:19]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-06-21 04:38:19]

Try jobs failed on following builders:
  win_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/win_blink_rel/builds/13022)

[Mike West, 2014-06-21 07:29:54]

The CQ bit was checked by mkwst@chromium.org

[commit-bot: I haz the power, 2014-06-21 07:30:42]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mkwst@chromium.org/324013003/40001

[commit-bot: I haz the power, 2014-06-21 09:21:05]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  win_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/win_blink_rel/builds/13027)

[commit-bot: I haz the power, 2014-06-21 10:09:19]

Change committed as 176681