Instrumented libraries: fix NSS build.

third_party/instrumented_libraries/download_build_install.py

 #!/usr/bin/python
 # Copyright 2013 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.
 
 """Downloads, builds (with instrumentation) and installs shared libraries."""
 
 import argparse
 import os
 import platform
@@ skipping 103 matching lines @@
   # Do an optimized build.
   make_args.append('BUILD_OPT=1')
   # Set USE_64=1 on x86_64 systems.
   if platform.architecture()[0] == '64bit':
     make_args.append('USE_64=1')
   # Passing C(XX)FLAGS overrides the defaults, and EXTRA_C(XX)FLAGS is not
   # supported. Append our extra flags to CC/CXX.
   make_args.append('CC="%s %s"' % (environment['CC'], environment['CFLAGS']))
   make_args.append('CXX="%s %s"' %
                    (environment['CXX'], environment['CXXFLAGS']))
-  # We need to override ZDEFS_FLAGS at least to prevent -Wl,-z,defs.
-  # Might as well use this to pass the linker flags, since ZDEF_FLAGS is always
+  # We need to override ZDEFS_FLAG at least to prevent -Wl,-z,defs.
+  # Might as well use this to pass the linker flags, since ZDEF_FLAG is always
   # added during linking on Linux.
   make_args.append('ZDEFS_FLAG="-Wl,-z,nodefs %s"' % environment['LDFLAGS'])
   make_args.append('NSPR_INCLUDE_DIR=/usr/include/nspr')
   make_args.append('NSPR_LIB_DIR=%s/lib' % install_prefix)
   make_args.append('NSS_ENABLE_ECC=1')
+  # Make sure we don't override the default flags.
+  for variable in ['CFLAGS', 'CXXFLAGS', 'LDFLAGS']:
+    del environment[variable]
   with ScopedChangeDirectory('nss') as cd_nss:
     # -j is not supported
     shell_call('make %s' % ' '.join(make_args), parsed_arguments.verbose,
                environment)
     # 'make install' is not supported. Copy the DSOs manually.
     install_dir = '%s/lib/' % install_prefix
     for (dirpath, dirnames, filenames) in os.walk('./lib/'):
       for filename in filenames:
         if filename.endswith('.so'):
           full_path = os.path.join(dirpath, filename)
@@ skipping 217 matching lines @@
   os.chdir(get_script_absolute_path())
   # Ensure all build dependencies are installed.
   if parsed_arguments.check_build_deps:
     check_package_build_dependencies(parsed_arguments.package)
 
   download_build_install(parsed_arguments)
 
 
 if __name__ == '__main__':
   main()