This CL is based on the patch:

This CL is based on the patch:
   http://codereview.chromium.org/8416025

Use GYP to build nacl_irt

Converts Chrome from using scons to using GYP when building nacl_irt.
This change causes chrome to use GYP based components for untrusted
code. As a benifit, GYP will no longer need to run and scrape scons
output to determine irt dependencies. This also allows us to avoid
invoking scons during the build process.
We roll NaCl deps to get a fix for a simultaneous 32/64 bit build
issue on Windows.

This broke the mac build due to a missing dependency where pthread.h was
unavailable.  This header gets copied to the correct location during the
prep_toolchain action.  I've added the appropriate dependency shown bellow
to the original patch.

This add the addition dependency to ppruntime
      'dependencies': [
        '<(DEPTH)/native_client/src/tools.gyp:prep_toolchain'
      ],

TEST= try
BUG= http://code.google.com/p/chromium/issues/detail?id=96782
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=108361

[noelallen1, 2011-11-01 18:57:26]

PTAL when you get a chance.  It's the same patch as before but with the missing
dependency on prep_toolchain.
While I was at it, I verified that all dependencies of nacl_irt already depended
on prep_toolchain as appropriate.

[dmichael (off chromium), 2011-11-01 19:04:09]

LGTM, just some nits.

http://codereview.chromium.org/8440004/diff/1001/chrome/nacl.gypi
File chrome/nacl.gypi (right):

http://codereview.chromium.org/8440004/diff/1001/chrome/nacl.gypi#newcode75
chrome/nacl.gypi:75: #issue
nit: space after #

http://codereview.chromium.org/8440004/diff/1001/ppapi/native_client/native_c...
File ppapi/native_client/native_client.gyp (right):

http://codereview.chromium.org/8440004/diff/1001/ppapi/native_client/native_c...
ppapi/native_client/native_client.gyp:44:
'-Wl,--section-start,.rodata=0x3ef00000',
nit: It would be nice to have some link or other reference for these magic
numbers.