Remove unused blink_gc_plugin_flags.py script.

tools/clang/scripts/blink_gc_plugin_flags.py

-#!/usr/bin/env python
-# Copyright 2015 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.
-
-# This script returns the flags that should be passed to clang.
-
-# TODO(sof): the script can be removed when/once gyp support is retired;
-# unused with gn.
-
-import os
-import sys
-
-THIS_DIR = os.path.abspath(os.path.dirname(__file__))
-SRC_DIR = os.path.join(THIS_DIR, '..', '..', '..')
-CLANG_LIB_PATH = os.path.normpath(os.path.join(
-    SRC_DIR, 'third_party', 'llvm-build', 'Release+Asserts', 'lib'))
-
-FLAGS = '-Xclang -add-plugin -Xclang blink-gc-plugin'
-PREFIX= ' -Xclang -plugin-arg-blink-gc-plugin -Xclang '
-
-for arg in sys.argv[1:]:
-  if arg == 'dump-graph=1':
-    FLAGS += PREFIX + 'dump-graph'
-  elif arg == 'warn-unneeded-finalizer=1':
-    FLAGS += PREFIX + 'warn-unneeded-finalizer'
-  elif arg.startswith('custom_clang_lib_path='):
-    CLANG_LIB_PATH = arg[len('custom_clang_lib_path='):]
-  elif arg == 'target_os=ios':
-    sys.stderr.write('error: blink is unsupported on iOS\n')
-    sys.exit(1)
-
-if not sys.platform in ['win32', 'cygwin']:
-  LIBSUFFIX = 'dylib' if sys.platform == 'darwin' else 'so'
-  FLAGS = ('-Xclang -load -Xclang "%s/libBlinkGCPlugin.%s" ' + FLAGS) % \
-           (CLANG_LIB_PATH, LIBSUFFIX)
-
-print FLAGS