Turn on prefetching in webkit builds

Turn on prefetching in webkit builds

After http://codereview.chromium.org/2847093/show lands, I'll land
this CL which modifies our build controls for webkit to turn on
prefetching.

This change might require builders to be clobbered, and by making it
so small, I'm sure a sherriff will see what's up.  However, I don't
believe it will actually require a clobber, since there's no unit
tests for prefetching (only functional tests and dumprendertree tests
in webkit).

TBR=tonyg@chromium.org
BUG=none
TEST=http://gemal.dk/browserspy/prefetching.php

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=54509

[cbentzel, 2010-07-31 12:24:51]

This CL also incorporates the prefetch-disabled-by-default logic from
http://codereview.chromium.org/2847093/show

This should just have the features_override.gypi change.

[gavinp, 2010-07-31 12:28:15]

On 2010/07/31 12:24:51, cbentzel wrote:
> This CL also incorporates the prefetch-disabled-by-default logic from
> http://codereview.chromium.org/2847093/show
> 
> This should just have the features_override.gypi change.

That's correct; that's why I was careful to do two uploads: the first one shows
the logic from the incident you pasted, and the second one incorporates the
diffs specific to this CL.

That's all that's in the repo, however the git cl upload showed both (it diffs
against trunk).  When I commit, only the features_override.gypi will uploaded.

[cbentzel, 2010-07-31 12:33:26]

better way to do this with git is to create two branches. in this case, both
could be parallel branches off trunk. in other cases, second branch is off
first, and you can set the second one to track the first branch (git cl will
do diff against tracking branch if specified, otherwise trunk)

On Sat, Jul 31, 2010 at 8:28 AM, <gavinp@chromium.org> wrote:

> On 2010/07/31 12:24:51, cbentzel wrote:
>
>> This CL also incorporates the prefetch-disabled-by-default logic from
>> http://codereview.chromium.org/2847093/show
>>
>
>  This should just have the features_override.gypi change.
>>
>
> That's correct; that's why I was careful to do two uploads: the first one
> shows
> the logic from the incident you pasted, and the second one incorporates the
> diffs specific to this CL.
>
> That's all that's in the repo, however the git cl upload showed both (it
> diffs
> against trunk).  When I commit, only the features_override.gypi will
> uploaded.
>
>
>
> http://codereview.chromium.org/3080015/show
>

[gavinp, 2010-07-31 12:36:03]

i ended up just expicitly specifying which branch to diff against, worked fine.