Instrumented libraries: improve handling of custom patches.

third_party/instrumented_libraries/standard_instrumented_package_target.gypi

 # 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.
 
 # This file is meant to be included into a target for instrumented dynamic
 # packages and describes standard build action for most of the packages.
 
 {
   'target_name': '<(_sanitizer_type)-<(_package_name)',
   'type': 'none',
   'actions': [
     {
       'action_name': '<(_package_name)',
       'inputs': [
         # TODO(earthdok): reintroduce some sort of dependency
         # See http://crbug.com/343515
         #'download_build_install.py',
       ],
       'outputs': [
         '<(PRODUCT_DIR)/instrumented_libraries/<(_sanitizer_type)/<(_package_name).txt',
       ],
       'action': ['<(DEPTH)/third_party/instrumented_libraries/download_build_install.py',
         '--product-directory=<(PRODUCT_DIR)',
         '--package=<(_package_name)',
         '--intermediate-directory=<(INTERMEDIATE_DIR)',
         '--sanitizer-type=<(_sanitizer_type)',
         '--extra-configure-flags=>(_extra_configure_flags)',
         '--cflags=>(_package_cflags)',
         '--ldflags=>(_package_ldflags)',
+        '--patch=>(_patch)',
         '--run-before-build=>(_run_before_build)',
         '--cc=<(_cc)',
         '--cxx=<(_cxx)',
         '--jobs=>(_jobs)',
         '--build-method=>(_build_method)',
         '--sanitizer-blacklist=>(_sanitizer_blacklist)',
       ],
       'conditions': [
         ['verbose_libraries_build==1', {
           'action+': [
             '--verbose',
           ],
         }],
-      ]
+      ],
+      'target_conditions': [
+        ['">(_patch)"!=""', {
+          'inputs+': [
+            '>(_patch)',
+          ],
+        }],
+        ['">(_run_before_build)"!=""', {
+          'inputs+': [
+            '>(_run_before_build)',
+          ],
+        }],
+      ],
     },
   ],
 }