Referrer Policy: Add a flag to reduce `referer` granularity by default.

Referrer Policy: Add a flag to reduce `referer` granularity by default. [1/2]

If a site hasn't set an explicit referrer policy, this runtime-enabled
flag will strip the outgoing header down to an origin. Perhaps this is
a direction we could offer as a choice to users in the future? (Note that this
implementation does not yet effect reditects. That's something to fix later
if/when we want to look more closely at this kind of approach. Nothing worth
doing for a strawman...).

Adding this flag to help evaluate the impact such a change might have.

[1/2] Blink: This patch.
[2/2] Chromium: https://codereview.chromium.org/711033002

BUG=431711
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=185057

[Mike West, 2014-11-10 13:57:41]

mkwst@chromium.org changed reviewers:
+ jochen@chromium.org

[Mike West, 2014-11-10 13:57:42]

Does this seem like a reasonable approach to what we discussed?

-mike

[jochen (gone - plz use gerrit), 2014-11-10 14:53:19]

lgtm

https://codereview.chromium.org/684683003/diff/1/Source/platform/weborigin/Se...
File Source/platform/weborigin/SecurityPolicy.cpp (right):

https://codereview.chromium.org/684683003/diff/1/Source/platform/weborigin/Se...
Source/platform/weborigin/SecurityPolicy.cpp:99: return
Referrer(shouldHideReferrer(url, referrer) ? String() : origin + "/",
referrerPolicy);
why not NoReferrerWhenDowngrade instead of referrerPolicy?

https://codereview.chromium.org/684683003/diff/1/Source/platform/weborigin/Se...
Source/platform/weborigin/SecurityPolicy.cpp:99: return
Referrer(shouldHideReferrer(url, referrer) ? String() : origin + "/",
referrerPolicy);
why not NoReferrerWhenDowngrade instead of referrerPolicy?

[Mike West, 2014-11-10 15:13:45]

Thanks!

https://codereview.chromium.org/684683003/diff/1/Source/platform/weborigin/Se...
File Source/platform/weborigin/SecurityPolicy.cpp (right):

https://codereview.chromium.org/684683003/diff/1/Source/platform/weborigin/Se...
Source/platform/weborigin/SecurityPolicy.cpp:99: return
Referrer(shouldHideReferrer(url, referrer) ? String() : origin + "/",
referrerPolicy);
On 2014/11/10 14:53:19, jochen (OOO) wrote:
> why not NoReferrerWhenDowngrade instead of referrerPolicy?

Because that would break the eventual redirect processing; we need to know that
we're in default mode through the lifetime of the referrer if we want to handle
navigation from 'example.com' to ('example.com' (301) -> 'notexample.com').

Does that make sense, or is there an easier way?

[Mike West, 2014-11-10 16:15:42]

The CQ bit was checked by mkwst@chromium.org

[commit-bot: I haz the power, 2014-11-10 16:16:50]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/684683003/1

[commit-bot: I haz the power, 2014-11-10 18:04:39]

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

[commit-bot: I haz the power, 2014-11-10 18:04:40]

Try jobs failed on following builders:
  win_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/win_blink_rel/builds/35624)

[Mike West, 2014-11-10 18:40:39]

The CQ bit was checked by mkwst@chromium.org

[commit-bot: I haz the power, 2014-11-10 18:41:14]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/684683003/1

[commit-bot: I haz the power, 2014-11-10 19:38:09]

Committed patchset #1 (id:1) as 185057