Move mac_find_sdk out of gyp directory

build/standalone.gypi

 # Copyright 2014 PDFium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Definitions to be used when building stand-alone PDFium binaries.
 
 {
   'variables': {
     'component%': 'static_library',
     'clang%': 0,
@@ skipping 436 matching lines @@
         ],
       }],  # OS=="win"
       ['OS=="mac"', {
         'target_conditions': [
           ['_type!="static_library"', {
             'xcode_settings': {'OTHER_LDFLAGS': ['-Wl,-search_paths_first']},
           }],
         ],  # target_conditions
         'variables': {
           'mac_sdk_min': '10.10',
-          'mac_sdk%': '<!(python <(DEPTH)/build/gyp/tools/mac_find_sdk.py <(mac_sdk_min))',
+          'mac_sdk%': '<!(python <(DEPTH)/build/mac_find_sdk.py <(mac_sdk_min))',
         },
         'xcode_settings': {
           'SDKROOT': 'macosx<(mac_sdk)',  # -isysroot
           # See comment in Chromium's common.gypi for why this is needed.
           'SYMROOT': '<(DEPTH)/xcodebuild',
         },
       }],  # OS=="mac"
       ['v8_use_external_startup_data==1', {
         'defines': [
           'V8_USE_EXTERNAL_STARTUP_DATA',
@@ skipping 30 matching lines @@
       ],
     }],  # OS=="win"
     ["use_goma==1", {
       'make_global_settings': [
         ['CC_wrapper', '<(gomadir)/gomacc'],
         ['CXX_wrapper', '<(gomadir)/gomacc'],
       ],
     }],  # use_goma==1
   ],
 }