Remove prerender sessionStorage namespace merging (1/2)

Remove prerender sessionStorage namespace merging (1/2)

This removes the additions in chrome/, but not the underlying content/
dom_storage changes.

BUG=440539
Committed: https://crrev.com/1f9befb67a3592ae9e15e58edc0b5fdd421ff6c6
Cr-Commit-Position: refs/heads/master@{#311514}

[davidben, 2014-12-11 01:01:49]

davidben@chromium.org changed reviewers:
+ mmenke@chromium.org

[davidben, 2014-12-11 01:01:50]

This CL is split in two for ease of reviewing. The full version is here:
https://codereview.chromium.org/757723002/

[mmenke, 2014-12-12 16:04:49]

https://codereview.chromium.org/797443002/diff/1/chrome/browser/prerender/pre...
File chrome/browser/prerender/prerender_contents.cc (right):

https://codereview.chromium.org/797443002/diff/1/chrome/browser/prerender/pre...
chrome/browser/prerender/prerender_contents.cc:584: if
(session_storage_namespace &&
I believe the "session_storage_namespace &&" should now be removed.

https://codereview.chromium.org/797443002/diff/1/chrome/browser/prerender/pre...
File chrome/browser/prerender/prerender_field_trial.cc (right):

https://codereview.chromium.org/797443002/diff/1/chrome/browser/prerender/pre...
chrome/browser/prerender/prerender_field_trial.cc:485: }
Wow...We should figure out which of these field trials no one cares about, and
rip them all out.

https://codereview.chromium.org/797443002/diff/1/chrome/browser/prerender/pre...
File chrome/browser/prerender/prerender_local_predictor.h (right):

https://codereview.chromium.org/797443002/diff/1/chrome/browser/prerender/pre...
chrome/browser/prerender/prerender_local_predictor.h:148:
EVENT_ISSUE_PRERENDER_PREFETCH_ISSUED = 95,
I think some of these can be commented out as obsolete...

https://codereview.chromium.org/797443002/diff/1/chrome/browser/prerender/pre...
File chrome/browser/prerender/prerender_manager.cc (right):

https://codereview.chromium.org/797443002/diff/1/chrome/browser/prerender/pre...
chrome/browser/prerender/prerender_manager.cc:426: // No need to merge; swap
synchronously.
Merge?  What's that?  :)

https://codereview.chromium.org/797443002/diff/1/chrome/browser/prerender/pre...
chrome/browser/prerender/prerender_manager.cc:451: }
nit:  Remove braces

https://codereview.chromium.org/797443002/diff/1/chrome/browser/ui/browser_na...
File chrome/browser/ui/browser_navigator.cc (right):

https://codereview.chromium.org/797443002/diff/1/chrome/browser/ui/browser_na...
chrome/browser/ui/browser_navigator.cc:627: swapped_in_prerender =
SwapInPrerender(params->url, params);
Before the merge stuff, didn't we used to cancel on session storage mismatch, as
the prerender was probably intended for the navigation we can't use it for?  Or
am I misremembering?

[davidben, 2014-12-12 20:41:20]

https://codereview.chromium.org/797443002/diff/1/chrome/browser/prerender/pre...
File chrome/browser/prerender/prerender_contents.cc (right):

https://codereview.chromium.org/797443002/diff/1/chrome/browser/prerender/pre...
chrome/browser/prerender/prerender_contents.cc:584: if
(session_storage_namespace &&
On 2014/12/12 16:04:48, mmenke wrote:
> I believe the "session_storage_namespace &&" should now be removed.

There's still places that pass in NULL. Though I think, apart from tests, it's
just PrerenderLocalPredictor that I still need to tease apart. I'll add a TODO.

https://codereview.chromium.org/797443002/diff/1/chrome/browser/prerender/pre...
File chrome/browser/prerender/prerender_field_trial.cc (right):

https://codereview.chromium.org/797443002/diff/1/chrome/browser/prerender/pre...
chrome/browser/prerender/prerender_field_trial.cc:485: }
On 2014/12/12 16:04:48, mmenke wrote:
> Wow...We should figure out which of these field trials no one cares about, and
> rip them all out.

Agreed.

https://codereview.chromium.org/797443002/diff/1/chrome/browser/prerender/pre...
File chrome/browser/prerender/prerender_local_predictor.h (right):

https://codereview.chromium.org/797443002/diff/1/chrome/browser/prerender/pre...
chrome/browser/prerender/prerender_local_predictor.h:148:
EVENT_ISSUE_PRERENDER_PREFETCH_ISSUED = 95,
On 2014/12/12 16:04:48, mmenke wrote:
> I think some of these can be commented out as obsolete...

Done. I pruned all the unused ones. Hopefully we can just drop it altogether.
I'm sure none of these are of any use to prefetch.

https://codereview.chromium.org/797443002/diff/1/chrome/browser/prerender/pre...
File chrome/browser/prerender/prerender_manager.cc (right):

https://codereview.chromium.org/797443002/diff/1/chrome/browser/prerender/pre...
chrome/browser/prerender/prerender_manager.cc:426: // No need to merge; swap
synchronously.
On 2014/12/12 16:04:48, mmenke wrote:
> Merge?  What's that?  :)

Done.

https://codereview.chromium.org/797443002/diff/1/chrome/browser/prerender/pre...
chrome/browser/prerender/prerender_manager.cc:451: }
On 2014/12/12 16:04:48, mmenke wrote:
> nit:  Remove braces

Done.

https://codereview.chromium.org/797443002/diff/1/chrome/browser/ui/browser_na...
File chrome/browser/ui/browser_navigator.cc (right):

https://codereview.chromium.org/797443002/diff/1/chrome/browser/ui/browser_na...
chrome/browser/ui/browser_navigator.cc:627: swapped_in_prerender =
SwapInPrerender(params->url, params);
On 2014/12/12 16:04:48, mmenke wrote:
> Before the merge stuff, didn't we used to cancel on session storage mismatch,
as
> the prerender was probably intended for the navigation we can't use it for? 
Or
> am I misremembering?

Looks like we stopped doing it in
https://chromiumcodereview.appspot.com/10553029. It now just figures into the
lookup, which is probably better? I think one WC's prerenders shouldn't interact
with another's if possible.

[mmenke, 2014-12-12 21:41:07]

LGTM

[mmenke, 2014-12-12 21:42:45]

On 2014/12/12 21:41:07, mmenke wrote:
> LGTM

Wait...you removed more than one histogram.

Also removed Prerender.SessionStorageNamespaceMergeTime.

[davidben, 2014-12-12 21:59:14]

On 2014/12/12 21:42:45, mmenke wrote:
> Wait...you removed more than one histogram.
> 
> Also removed Prerender.SessionStorageNamespaceMergeTime.

Done.

[davidben, 2014-12-12 22:00:47]

davidben@chromium.org changed reviewers:
+ isherman@chromium.org, sky@chromium.org

[davidben, 2014-12-12 22:00:48]

+isherman for histograms.xml
+sky for chrome/OWNERS. Just the ones that don't have 'prerender' in the name.

[Ilya Sherman, 2014-12-12 22:03:27]

histograms.xml LGTM

[sky, 2014-12-13 00:10:55]

Said files LGTM

[davidben, 2015-01-05 21:48:30]

(Holding off on landing this until after branch point. It's basically a revert,
but it's a giant revert.)

[mmenke, 2015-01-14 16:06:09]

On 2015/01/05 21:48:30, David Benjamin wrote:
> (Holding off on landing this until after branch point. It's basically a
revert,
> but it's a giant revert.)

David:  Now that we're past branch, think we're good to land this?

[davidben, 2015-01-14 16:28:54]

On 2015/01/14 16:06:09, mmenke wrote:
> On 2015/01/05 21:48:30, David Benjamin wrote:
> > (Holding off on landing this until after branch point. It's basically a
> revert,
> > but it's a giant revert.)
> 
> David:  Now that we're past branch, think we're good to land this?

Yup. Rebasing and landing now.

[davidben, 2015-01-14 16:37:35]

The CQ bit was checked by davidben@chromium.org

[commit-bot: I haz the power, 2015-01-14 16:38:38]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/797443002/80001

[commit-bot: I haz the power, 2015-01-14 18:14:33]

Committed patchset #5 (id:80001)

[commit-bot: I haz the power, 2015-01-14 18:16:18]

Patchset 5 (id:??) landed as
https://crrev.com/1f9befb67a3592ae9e15e58edc0b5fdd421ff6c6
Cr-Commit-Position: refs/heads/master@{#311514}