GN: Do not build NaCl toolchain libraries locally

The NaCl toolchains include various libraries, used to build NaCl
executables, whose sources live in //native_client/src/untrusted.
For a long time the intent has been to just use the library binaries
supplied in the NaCl toolchains rather than building these locally
as part of the Chromium components built with NaCl toolchains.  But
the GYP files, and the GN files written from their model, have
explicit dependencies on //native_client/src/untrusted/* components
that cause them to be rebuilt locally.  This rebuilding is
unnecessary and slows Chromium builds down a little.  Furthermore,
the GN rules for NaCl toolchains are not fully compatible with
building all of these low-level internal components of the NaCl
toolchains' runtime and in some circumstances have errors building
them.  To avoid all this, replace various deps entries on those
library targets with libs entries that refer to the libraries
already available in a NaCl toolchain.  The various nacl_*_private
libraries are not included in the toolchains and so still need to be
built locally as they are now.

The corresponding GYP rules do still have the dependencies that cause
the toolchain libraries to be rebuilt, so with this change GN and GYP
are now doing things differently.  I'm not touching the GYP rules for
this because they work fine as they are and I'm avoiding perturbing the
fragile GYP situation while we make GN more perfect.

BUG= 565493
R=bradnelson@chromium.org, ncbray@chromium.org, plundblad@chromium.org

Review URL: https://codereview.chromium.org/1514223003

Cr-Commit-Position: refs/heads/master@{#365167}

1 files changed, 0 insertions, 4 deletions

diff --git a/ppapi/native_client/BUILD.gn b/ppapi/native_client/BUILD.gn
index 14138b3..374d970 100644
--- a/ppapi/native_client/BUILD.gn
+++ b/ppapi/native_client/BUILD.gn
@@ -10,10 +10,6 @@ if (is_nacl) {
     deps = [
       "//ppapi/native_client/src/untrusted/irt_stub:ppapi_stub_lib",
     ]
-    if (!is_nacl_glibc) {
-      # Glibc has its version of pthread library.
-      deps += [ "//native_client/src/untrusted/pthread" ]
-    }
   }
 
   executable("nacl_irt") {