Update usage of Proguard in clank after moving Proguard to third_party.

build/java_apk.gypi

 # Copyright (c) 2012 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 to provide a rule
 # to build Android APKs in a consistent manner.
 #
 # To use this, create a gyp target with the following form:
 # {
 #   'target_name': 'my_package_apk',
@@ skipping 977 matching lines @@
         '--android-sdk', '<(android_sdk)',
         '--android-sdk-tools', '<(android_sdk_tools)',
         '--android-sdk-jar', '<(android_sdk_jar)',
 
         '--input-jars-paths=>(proguard_input_jar_paths)',
         '--proguard-configs=>(proguard_flags_paths)',
 
         '--test-jar-path', '<(test_jar_path)',
         '--obfuscated-jar-path', '<(obfuscated_jar_path)',
 
-        '--proguard-jar-path', '<(android_sdk_root)/tools/proguard/lib/proguard.jar',
+        '--proguard-jar-path', '<(DEPTH)/third_party/proguard/lib/proguard.jar',
 
         '--stamp', '<(obfuscate_stamp)',
 
         '>@(additional_obfuscate_options)',
       ],
     },
     {
       'action_name': 'dex_<(_target_name)',
       'variables': {
         'dex_input_paths': [
@@ skipping 57 matching lines @@
             'native_libs_dir': '<(apk_package_native_libs_dir)',
           }, {
             'native_libs_dir': '<(DEPTH)/build/android/ant/empty/res',
           }],
         ],
       },
       'includes': ['android/apkbuilder_action.gypi'],
     },
   ],
 }