Build NaCl browser tests with GN

ppapi/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 copy("copy_test_files") {
   visibility = [ ":*" ]
   sources = [
     # Keep "test_case.html.mock-http-headers" with "test_case.html".
     "tests/ppapi_nacl_tests_newlib.nmf",
     "tests/test_case.html",
@@ skipping 132 matching lines @@
   sources = [
     "tools/pepper_hash_for_uma.cc",
   ]
 
   deps = [
     "//base",
     "//build/config/sanitizers:deps",
   ]
 }
 
-source_set("ppapi_cpp_lib") {
+static_library("ppapi_cpp_lib") {
+  # This library is distributed as a part of the SDK and as such has to
+  # be a static library rather than a source set.
   sources = ppapi_sources.cpp_source_files
   sources += [
     "cpp/module_embedder.h",
     "cpp/ppp_entrypoints.cc",
   ]
   deps = [
     "//build/config/nacl:nacl_base",
   ]
 }
 
@@ skipping 180 matching lines @@
       ":ppapi_nacl_tests_nmf(//build/toolchain/nacl:glibc_${target_cpu})",
     ]
     if (enable_pnacl) {
       data_deps += [
         ":ppapi_nacl_tests_nmf(//build/toolchain/nacl:newlib_pnacl)",
         ":ppapi_nacl_tests_pnacl_nonsfi_nmf(//build/toolchain/nacl:newlib_pnacl_nonsfi)",
       ]
     }
   }
 }