Beginnings of moving more stuff from build_sdk.py to GYP.

Beginnings of moving more stuff from build_sdk.py to GYP.

Adds a new target to all.gyp: chromium_builder_nacl_sdk
Adds a native_client_sdk gyp file: it depends on nacl_core_sdk from the
native_client repo, but also builds and copies ppapi libraries to the toolchain
directories.

Retry of https://codereview.chromium.org/11413075/.
This one failed because I didn't check for disable_nacl=1.

Which was a retry of http://codereview.chromium.org/11299081/.
Which was a retry of http://codereview.chromium.org/11363045/.
Failed both of these times because of a separate NaCl build issue that was
resolved by http://crrev.com/168621.

BUG=none
TBR=noelallen@chromium.org


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=169532

[commit-bot: I haz the power, 2012-11-21 18:55:57]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/binji@chromium.org/11316139/1

[commit-bot: I haz the power, 2012-11-26 21:21:41]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/binji@chromium.org/11316139/1

[commit-bot: I haz the power, 2012-11-26 23:41:45]

Change committed as 169532