Split out blimp client build config to its own config.gni file

Split out blimp client build config to its own config.gni file

Up until now, only GN targets in //blimp/client/core needed to know
about the declared argument |enable_blimp_client|.

For using the flag in the internal build files though, those
.gni-files need to be able to refer to the flag. Since they can not
include //blimp/client/core/BUILD.gn, this CL extracts the declaration
of the argument into its own .gni-file, that is imported by
//blimp/client/core/BUILD.gn.

This makes it possible for other GN code to also be able to read the
declared argument.

BUG=608765
Review-Url: https://codereview.chromium.org/2225233002
Cr-Commit-Position: refs/heads/master@{#410532}
(cherry picked from commit 179e0366187c3062f487fe55629872185fb5fb4a)

Committed: https://chromium.googlesource.com/chromium/src/+/f17ac022416b6b44e29bb49c5b5f94f7ddcacfbf

[amineer, 2016-08-09 17:53:25]

Description was changed from

==========
Split out blimp client build config to its own config.gni file

Up until now, only GN targets in //blimp/client/core needed to know
about the declared argument |enable_blimp_client|.

For using the flag in the internal build files though, those
.gni-files need to be able to refer to the flag. Since they can not
include //blimp/client/core/BUILD.gn, this CL extracts the declaration
of the argument into its own .gni-file, that is imported by
//blimp/client/core/BUILD.gn.

This makes it possible for other GN code to also be able to read the
declared argument.

BUG=608765

Review-Url: https://codereview.chromium.org/2225233002
Cr-Commit-Position: refs/heads/master@{#410532}
(cherry picked from commit 179e0366187c3062f487fe55629872185fb5fb4a)
==========

to

==========
Split out blimp client build config to its own config.gni file

Up until now, only GN targets in //blimp/client/core needed to know
about the declared argument |enable_blimp_client|.

For using the flag in the internal build files though, those
.gni-files need to be able to refer to the flag. Since they can not
include //blimp/client/core/BUILD.gn, this CL extracts the declaration
of the argument into its own .gni-file, that is imported by
//blimp/client/core/BUILD.gn.

This makes it possible for other GN code to also be able to read the
declared argument.

BUG=608765

Review-Url: https://codereview.chromium.org/2225233002
Cr-Commit-Position: refs/heads/master@{#410532}
(cherry picked from commit 179e0366187c3062f487fe55629872185fb5fb4a)

Committed:
https://chromium.googlesource.com/chromium/src/+/f17ac022416b6b44e29bb49c5b5f...
==========

[amineer, 2016-08-09 17:53:27]

Committed patchset #1 (id:1) manually as
f17ac022416b6b44e29bb49c5b5f94f7ddcacfbf.