Move v8_use_external_startup_data out of //build/config:feature_flags.

Move v8_use_external_startup_data out of //build/config:feature_flags.

This CL removes the global define of V8_USE_EXTERNAL_STARTUP_DATA from
the list in //build/config:feature_flags, and updates the individual
call sites to use the definition as appropriate.

By making this change, //build/config will not need to import
//build_overrides/v8.gni, and that will make it easier for other
projects that use GN to use //build without needing to create a
v8 overrides file.

R=brettw@chromium.org
BUG=541791
Committed: https://crrev.com/a22b0730051957c6024527154919daf8de71afea
Cr-Commit-Position: refs/heads/master@{#355401}

[Dirk Pranke, 2015-10-20 00:44:38]

This patch depends on https://codereview.chromium.org/1415773003/

[Dirk Pranke, 2015-10-20 00:45:00]

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

[Dirk Pranke, 2015-10-20 00:45:01]

Please take a look ... does this seem like a good idea?

[brettw, 2015-10-20 02:44:41]

https://codereview.chromium.org/1413893003/diff/1/chrome/plugin/BUILD.gn
File chrome/plugin/BUILD.gn (right):

https://codereview.chromium.org/1413893003/diff/1/chrome/plugin/BUILD.gn#newc...
chrome/plugin/BUILD.gn:15: configs += [ "//v8:external_startup_data" ]
Did you consider making the config check the flag value and set the define or
not according to that? Then you can avoid the conditions and imports in each of
these files.

[Dirk Pranke, 2015-10-20 03:00:16]

https://codereview.chromium.org/1413893003/diff/1/chrome/plugin/BUILD.gn
File chrome/plugin/BUILD.gn (right):

https://codereview.chromium.org/1413893003/diff/1/chrome/plugin/BUILD.gn#newc...
chrome/plugin/BUILD.gn:15: configs += [ "//v8:external_startup_data" ]
On 2015/10/20 02:44:41, brettw wrote:
> Did you consider making the config check the flag value and set the define or
> not according to that? Then you can avoid the conditions and imports in each
of
> these files.

I did, yes. 

In some cases (e.g., net) we have to do additional logic based on the flag as
well, so I thought it might be better to always make everyone check the flag to
be consistent.

I can make the config check the flag instead if you think that would be better
(or, at least, work up a patch that does that for you to compare the two).

[brettw, 2015-10-20 03:05:02]

I think moving the check to the config would be cleaner.

[jochen (gone - plz use gerrit), 2015-10-20 08:04:49]

i defer to brett here

[Dirk Pranke, 2015-10-20 21:24:01]

Patchset #2 (id:20001) has been deleted

[Dirk Pranke, 2015-10-20 21:25:30]

brettw, please take another look?

[brettw, 2015-10-20 23:43:35]

lgtm

[Dirk Pranke, 2015-10-21 19:54:19]

The CQ bit was checked by dpranke@chromium.org

[commit-bot: I haz the power, 2015-10-21 19:55:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1413893003/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1413893003/40001

[commit-bot: I haz the power, 2015-10-21 21:15:19]

Committed patchset #2 (id:40001)

[commit-bot: I haz the power, 2015-10-21 21:16:00]

Patchset 2 (id:??) landed as
https://crrev.com/a22b0730051957c6024527154919daf8de71afea
Cr-Commit-Position: refs/heads/master@{#355401}