Migrate users from "WebKit" flag to "Web Platform".

Migrate users from "WebKit" flag to "Web Platform".

We changed the name of the "Experimental WebKit Features" flag, and changed
the actual flag at the same time[1]. I decided at the time to simply throw away
the old flag; I've been reliably informed that developers aren't particularly
thrilled with that decision. "Why have my experimental features stopped
working?" they ask. "Didn't you read my G+ post?" isn't a particularly helpful
answer, especially since most people (unbelievably!) don't follow me on
The Internets™.

This patch hacks a migration system into about:flags, which I hope we never
ever have to use again, and can safely throw away after a release cycle or two.

[1]: https://codereview.chromium.org/14940009/

[email protected],[email protected]

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=212794

[Mike West, 2013-07-18 14:34:29]

pretty please?

[jochen (gone - plz use gerrit), 2013-07-18 14:51:57]

https://codereview.chromium.org/19520007/diff/1/chrome/browser/about_flags.cc
File chrome/browser/about_flags.cc (right):

https://codereview.chromium.org/19520007/diff/1/chrome/browser/about_flags.cc...
chrome/browser/about_flags.cc:311: 
why the empty line?

https://codereview.chromium.org/19520007/diff/1/chrome/browser/about_flags.cc...
chrome/browser/about_flags.cc:1628: const Experiment kDeprecatedExperiments[] =
{
can you add a comment describing how to add deprecated experiments here?

https://codereview.chromium.org/19520007/diff/1/chrome/browser/about_flags.cc...
chrome/browser/about_flags.cc:1735: printf("Known Experiments: %s\n",
experiments[i].internal_name);
?

https://codereview.chromium.org/19520007/diff/1/chrome/browser/about_flags.cc...
chrome/browser/about_flags.cc:1748: if
(enabled_experiments.count("enable-experimental-web-platform-features"))
?

https://codereview.chromium.org/19520007/diff/1/chrome/browser/about_flags.cc...
chrome/browser/about_flags.cc:2074: for (size_t i = 0; i <
ARRAYSIZE_UNSAFE(kDeprecatedExperiments); ++i) {
why is this needed?

[Mike West, 2013-07-19 13:46:44]

Hi Jochen, Nico, 

Can you take a quick look at this fairly hacky patch?

/cc the clever people who are interested in this.

-mike

[jochen (gone - plz use gerrit), 2013-07-19 13:50:41]

lgtm

https://codereview.chromium.org/19520007/diff/5001/chrome/browser/about_flags.cc
File chrome/browser/about_flags.cc (right):

https://codereview.chromium.org/19520007/diff/5001/chrome/browser/about_flags...
chrome/browser/about_flags.cc:1722:
experimentList->erase(experimentList->find(migrations[i].from));
nit. if you're using find() anyway, you can just store the iterator in a local
variable, then check that the iterator is != end() and if use, pass it to erase.

[commit-bot: I haz the power, 2013-07-20 16:26:12]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/[email protected]/19520007/5001

[commit-bot: I haz the power, 2013-07-20 18:14:42]

Change committed as 212794

[Nico, 2013-07-20 18:35:23]

https://chromiumcodereview.appspot.com/19520007/diff/5001/chrome/browser/abou...
File chrome/browser/about_flags.cc (right):

https://chromiumcodereview.appspot.com/19520007/diff/5001/chrome/browser/abou...
chrome/browser/about_flags.cc:1642: {"enable-experimental-webkit-features",
If you wanted to not have users to reset this, couldn't you just've kept
"enable-experimental-webkit-features" as the old flag name? The flag name isn't
exposed for anything as far as I know.