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 http://codereview.chromium.org/11299081/.
Which was a retry of http://codereview.chromium.org/11363045/.

Failed both times because of a separate NaCl build issue that was resolved by
http://crrev.com/168621.

BUG=none
TBR=noelallen@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=168921

[jeremya, 2012-11-21 01:02:37]

On a recently pulled build I'm getting the following error:

gyp: Unable to find targets in build file
E:\src\chromium\src\ppapi\native_client\native_client.gyp while loading
dependencies of
E:\src\chromium\src\native_client_sdk\src\build_tools\nacl_ppapi_sdk.gyp while
loading dependencies of E:\src\chromium\src\build\all.gyp while trying to load
E:\src\chromium\src\build\all.gyp

Looks related to this patch?

I am running 'gclient sync' with:
GYP_DEFINES="disable_nacl=1 component=shared_libarary"
GYP_GENERATORS=ninja

[noelallen1, 2012-11-21 01:33:48]

https://codereview.chromium.org/11413075/diff/1/build/all.gyp
File build/all.gyp (right):

https://codereview.chromium.org/11413075/diff/1/build/all.gyp#newcode353
build/all.gyp:353: {
You should conditionally depend nacl_ppapi_sdk and chrome_nacl_win64 to prevent
these GYP/GYPI files from getting loaded when disable_nacl!=0

[binji, 2012-11-21 02:26:01]

This CL has been reverted -- I'll make sure these use cases are covered in my
next try.