Count data deps even if it was already a regular dep

Count data deps even if it was already a regular dep

Previously GN's runtime deps computation would only count a target once, but
this ignores the fact that whether a target is a data dependency or a regular
one affects how it's added.

This patch revisits a target if it's depended on in a data dependency
even if it's already been seen as a regular dependency.

Enhance the runtime deps documentation.

Committed: https://crrev.com/295e07207149d215f749dffb68c9c56e1188bc4d
Cr-Commit-Position: refs/heads/master@{#339778}

[brettw, 2015-07-21 22:30:00]

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

[brettw, 2015-07-21 22:30:07]

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

[commit-bot: I haz the power, 2015-07-21 22:31:09]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1250883002/1

[Dirk Pranke, 2015-07-21 23:00:51]

lgtm w/ typo fixed.

https://codereview.chromium.org/1250883002/diff/1/tools/gn/runtime_deps.cc
File tools/gn/runtime_deps.cc (right):

https://codereview.chromium.org/1250883002/diff/1/tools/gn/runtime_deps.cc#ne...
tools/gn/runtime_deps.cc:175: "  build's paralellism would be unnecessarily
constrained.\n"
typo: parallelism

[commit-bot: I haz the power, 2015-07-21 23:02:55]

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

[commit-bot: I haz the power, 2015-07-21 23:02:56]

Dry run: This issue passed the CQ dry run.

[brettw, 2015-07-21 23:05:06]

The CQ bit was checked by brettw@chromium.org

[brettw, 2015-07-21 23:05:07]

The patchset sent to the CQ was uploaded after l-g-t-m from dpranke@chromium.org
Link to the patchset: https://codereview.chromium.org/1250883002/#ps20001
(title: "typo")

[commit-bot: I haz the power, 2015-07-21 23:05:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1250883002/20001

[commit-bot: I haz the power, 2015-07-21 23:31:17]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-07-21 23:32:22]

Patchset 2 (id:??) landed as
https://crrev.com/295e07207149d215f749dffb68c9c56e1188bc4d
Cr-Commit-Position: refs/heads/master@{#339778}