GN documentation updates.

GN documentation updates.

Mark the "copy" target as a target function so it appears in the correct section of "gn help".

Use get_target_outputs() in the template example, since you should generall do this instead of process_file_template.

Update docs for process_file_template to state that you should use get_target_outputs if possible.

R=cjhopman@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=269793

[cjhopman, 2014-05-07 20:19:18]

lgtm

https://codereview.chromium.org/270613006/diff/20001/tools/gn/functions.cc
File tools/gn/functions.cc (right):

https://codereview.chromium.org/270613006/diff/20001/tools/gn/functions.cc#ne...
tools/gn/functions.cc:650: INSERT_FUNCTION(Copy, true)
nit: Move this up into the group of other target functions

[brettw, 2014-05-07 23:03:24]

The CQ bit was checked by brettw@chromium.org

[commit-bot: I haz the power, 2014-05-07 23:06:35]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/brettw@chromium.org/270613006/40001

[commit-bot: I haz the power, 2014-05-08 07:37:19]

FYI, CQ is re-trying this CL (attempt #1).
Please consider checking whether the failures are real,
and report flakes to chrome-troopers@google.com.
The failing builders are:
  win_chromium_rel on tryserver.chromium

[commit-bot: I haz the power, 2014-05-08 20:27:55]

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

[commit-bot: I haz the power, 2014-05-08 20:27:56]

Try jobs failed on following builders:
  win_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_rel/buil...)

[brettw, 2014-05-12 16:19:30]

Committed patchset #3 manually as r269793 (presubmit successful).