Add "StaleWhileRevalidateCacheControl" runtime flag.

Add "StaleWhileRevalidateCacheControl" runtime flag.

stale-while-revalidate is an HTTP cache-control header[1][2] and we
would like to add a runtime enabled flag to control the Blink cache.
The flag is disabled by default. It will be enabled when the corresponding
flag is enabled in chrome://flags.

1: http://tools.ietf.org/html/rfc5861
2: https://docs.google.com/a/chromium.org/document/d/1nBhr25nSJgoyAh4S1-U5h2sH70Iz4RR0NAfXNL79G5Y/edit#heading=h.wu5anpnlvlfy

BUG=469560
R=ricea@chromium.org

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=192812

[yhirano, 2015-03-23 04:07:36]

yhirano@chromium.org changed reviewers:
+ ricea@chromium.org

[yhirano, 2015-03-23 04:09:43]

https://codereview.chromium.org/1031493002/diff/1/Source/platform/RuntimeEnab...
File Source/platform/RuntimeEnabledFeatures.in (right):

https://codereview.chromium.org/1031493002/diff/1/Source/platform/RuntimeEnab...
Source/platform/RuntimeEnabledFeatures.in:145: StaleWhileRevalidate
It's OK to add status=test if you want to enable the flag in tests.

[Adam Rice, 2015-03-26 12:28:55]

https://codereview.chromium.org/1031493002/diff/1/Source/platform/RuntimeEnab...
File Source/platform/RuntimeEnabledFeatures.in (right):

https://codereview.chromium.org/1031493002/diff/1/Source/platform/RuntimeEnab...
Source/platform/RuntimeEnabledFeatures.in:145: StaleWhileRevalidate
On 2015/03/23 04:09:43, yhirano wrote:
> It's OK to add status=test if you want to enable the flag in tests.

We want the flag to be synchronised between the browser and renderer, so this is
not ideal.

For testing I think I will just have a CL which turns it on by default which I
can send to the try bots without actually submitting it.

[yhirano, 2015-03-27 07:09:00]

https://codereview.chromium.org/1031493002/diff/1/Source/platform/RuntimeEnab...
File Source/platform/RuntimeEnabledFeatures.in (right):

https://codereview.chromium.org/1031493002/diff/1/Source/platform/RuntimeEnab...
Source/platform/RuntimeEnabledFeatures.in:145: StaleWhileRevalidate
On 2015/03/26 12:28:55, Adam Rice wrote:
> On 2015/03/23 04:09:43, yhirano wrote:
> > It's OK to add status=test if you want to enable the flag in tests.
> 
> We want the flag to be synchronised between the browser and renderer, so this
is
> not ideal.
> 
> For testing I think I will just have a CL which turns it on by default which I
> can send to the try bots without actually submitting it.

Does it mean you are fine with PS1?

[Adam Rice, 2015-03-27 12:39:27]

On 2015/03/27 07:09:00, yhirano wrote:
>
https://codereview.chromium.org/1031493002/diff/1/Source/platform/RuntimeEnab...
> File Source/platform/RuntimeEnabledFeatures.in (right):
> 
>
https://codereview.chromium.org/1031493002/diff/1/Source/platform/RuntimeEnab...
> Source/platform/RuntimeEnabledFeatures.in:145: StaleWhileRevalidate
> On 2015/03/26 12:28:55, Adam Rice wrote:
> > On 2015/03/23 04:09:43, yhirano wrote:
> > > It's OK to add status=test if you want to enable the flag in tests.
> > 
> > We want the flag to be synchronised between the browser and renderer, so
this
> is
> > not ideal.
> > 
> > For testing I think I will just have a CL which turns it on by default which
I
> > can send to the try bots without actually submitting it.
> 
> Does it mean you are fine with PS1?

Yes, PS1 LGTM.

[yhirano, 2015-03-30 11:11:35]

yhirano@chromium.org changed reviewers:
+ tkent@chromium.org

[yhirano, 2015-03-30 11:11:35]

+tkent for OWNER review.

[tkent, 2015-03-30 23:09:19]

I can't image what's this flag is for.  What's stale?  What's revalidated?  Is
it related to WebScoket, XHR, or Fetch API?

[yhirano, 2015-03-31 00:51:52]

On 2015/03/30 23:09:19, tkent wrote:
> I can't image what's this flag is for.  What's stale?  What's revalidated?  Is
> it related to WebScoket, XHR, or Fetch API?

[yhirano, 2015-03-31 00:52:06]

On 2015/03/31 00:51:52, yhirano wrote:
> On 2015/03/30 23:09:19, tkent wrote:
> > I can't image what's this flag is for.  What's stale?  What's revalidated? 
Is
> > it related to WebScoket, XHR, or Fetch API?

I updated the description.

[tkent, 2015-03-31 00:56:04]

On 2015/03/31 00:52:06, yhirano wrote:
> On 2015/03/31 00:51:52, yhirano wrote:
> > On 2015/03/30 23:09:19, tkent wrote:
> > > I can't image what's this flag is for.  What's stale?  What's revalidated?

> Is
> > > it related to WebScoket, XHR, or Fetch API?
> 
> I updated the description.

Thanks.  I'd like to name it "HTTPStaleWhileRevalidate," or something to
represent the Blink cache behavior change by the flag.

[yhirano, 2015-03-31 01:11:55]

On 2015/03/31 00:56:04, tkent wrote:
> On 2015/03/31 00:52:06, yhirano wrote:
> > On 2015/03/31 00:51:52, yhirano wrote:
> > > On 2015/03/30 23:09:19, tkent wrote:
> > > > I can't image what's this flag is for.  What's stale?  What's
revalidated?
> 
> > Is
> > > > it related to WebScoket, XHR, or Fetch API?
> > 
> > I updated the description.
> 
> Thanks.  I'd like to name it "HTTPStaleWhileRevalidate," or something to
> represent the Blink cache behavior change by the flag.

How about StaleWhileRevalidateCacheControl? I don't like adding "HTTP" prefix
because the first character will be uncapitalized automatically.

[tkent, 2015-03-31 01:15:28]

> How about StaleWhileRevalidateCacheControl? I don't like adding "HTTP" prefix
> because the first character will be uncapitalized automatically.

It sounds good.

[yhirano, 2015-03-31 06:50:04]

On 2015/03/31 01:15:28, tkent wrote:
> > How about StaleWhileRevalidateCacheControl? I don't like adding "HTTP"
prefix
> > because the first character will be uncapitalized automatically.
> 
> It sounds good.

Renamed. PTAL.

[tkent, 2015-03-31 06:54:53]

The CQ bit was checked by tkent@chromium.org

[tkent, 2015-03-31 06:54:53]

lgtm

[tkent, 2015-03-31 06:54:53]

The patchset sent to the CQ was uploaded after l-g-t-m from ricea@chromium.org
Link to the patchset: https://codereview.chromium.org/1031493002/#ps20001
(title: " ")

[commit-bot: I haz the power, 2015-03-31 06:55:19]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1031493002/20001

[commit-bot: I haz the power, 2015-03-31 08:42:50]

Committed patchset #2 (id:20001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=192812