Throw errors for nested targets in GN.

Throw errors for nested targets in GN.

People sometimes nest targets or configs, usually with the assumption that
this limits the visibility of a config to within a target. But this nesting
provides no visibility restrictions over declaring it outside of a block.

For clarity, force certain types of blocks to be non-nested.

Adds missing ordering documentation to the ldflags variable.

Committed: https://crrev.com/a88eb18a5cb883cbde7a1e055958642a8dafb4ac
Cr-Commit-Position: refs/heads/master@{#348186}

[brettw, 2015-08-31 19:28:35]

I'll land this after updating the current set of errors:
https://codereview.chromium.org/1318823008/ and 2 deps rolls.

[brettw, 2015-08-31 19:28:45]

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

[brettw, 2015-08-31 19:28:46]

I'll land this after updating the current set of errors:
https://codereview.chromium.org/1318823008/ and 2 deps rolls.

[brettw, 2015-08-31 19:29:00]

The CQ bit was checked by brettw@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-08-31 19:29:26]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1314773005/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1314773005/20001

[brettw, 2015-08-31 19:30:21]

Hold off for a sec, I have a tweak.

[brettw, 2015-08-31 19:37:43]

Ready to go again, slightly simplified.

[brettw, 2015-08-31 19:37:46]

The CQ bit was checked by brettw@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-08-31 19:38:22]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1314773005/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1314773005/40001

[commit-bot: I haz the power, 2015-08-31 19:53:43]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-31 19:53:44]

Dry run: This issue passed the CQ dry run.

[Dirk Pranke, 2015-08-31 20:15:27]

lgtm

[brettw, 2015-09-10 17:57:36]

The CQ bit was checked by brettw@chromium.org

[commit-bot: I haz the power, 2015-09-10 17:57:46]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1314773005/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1314773005/40001

[commit-bot: I haz the power, 2015-09-10 18:11:58]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-09-10 18:12:37]

Patchset 3 (id:??) landed as
https://crrev.com/a88eb18a5cb883cbde7a1e055958642a8dafb4ac
Cr-Commit-Position: refs/heads/master@{#348186}

[commit-bot: I haz the power, 2015-09-23 12:12:05]

Patchset 3 (id:??) landed as
https://crrev.com/a88eb18a5cb883cbde7a1e055958642a8dafb4ac
Cr-Commit-Position: refs/heads/master@{#348186}