chromium_tests: fix crash in deapply_patch on got_webkit_revision

scripts/slave/recipes/cronet.expected/android_cronet_mips_builder.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "\nimport os, sys\n\nbuild_path = sys.argv[1]\nif os.path.exists(build_path):\n  for (path, dir, files) in os.walk(build_path):\n    for cur_file in files:\n      if cur_file.endswith('index.lock'):\n        path_to_file = os.path.join(path, cur_file)\n        print 'deleting %s' % path_to_file\n        os.remove(path_to_file)\n",
       "[SLAVE_BUILD]"
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "cleanup index.lock",
@@ skipping 75 matching lines @@
     "name": "gclient sync",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
       "@@@STEP_LOG_LINE@json.output@  \"solutions\": {@@@",
       "@@@STEP_LOG_LINE@json.output@    \"src/\": {@@@",
       "@@@STEP_LOG_LINE@json.output@      \"revision\": 170242@@@",
       "@@@STEP_LOG_LINE@json.output@    }, @@@",
       "@@@STEP_LOG_LINE@json.output@    \"src/native_client/\": {@@@",
       "@@@STEP_LOG_LINE@json.output@      \"revision\": 274981@@@",
       "@@@STEP_LOG_LINE@json.output@    }, @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"src/third_party/WebKit/\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@      \"revision\": 124383@@@",
-      "@@@STEP_LOG_LINE@json.output@    }, @@@",
       "@@@STEP_LOG_LINE@json.output@    \"src/third_party/webrtc/\": {@@@",
       "@@@STEP_LOG_LINE@json.output@      \"revision\": 120644@@@",
       "@@@STEP_LOG_LINE@json.output@    }, @@@",
       "@@@STEP_LOG_LINE@json.output@    \"src/tools/swarming_client/\": {@@@",
       "@@@STEP_LOG_LINE@json.output@      \"revision\": 276089@@@",
       "@@@STEP_LOG_LINE@json.output@    }, @@@",
       "@@@STEP_LOG_LINE@json.output@    \"src/v8/\": {@@@",
       "@@@STEP_LOG_LINE@json.output@      \"revision\": 43426@@@",
       "@@@STEP_LOG_LINE@json.output@    }@@@",
       "@@@STEP_LOG_LINE@json.output@  }@@@",
       "@@@STEP_LOG_LINE@json.output@}@@@",
       "@@@STEP_LOG_END@json.output@@@",
+      "@@@SET_BUILD_PROPERTY@got_webrtc_revision@120644@@@",
+      "@@@SET_BUILD_PROPERTY@got_v8_revision@43426@@@",
+      "@@@SET_BUILD_PROPERTY@got_src_revision@170242@@@",
       "@@@SET_BUILD_PROPERTY@got_nacl_revision@274981@@@",
-      "@@@SET_BUILD_PROPERTY@got_webkit_revision@124383@@@",
-      "@@@SET_BUILD_PROPERTY@got_src_revision@170242@@@",
-      "@@@SET_BUILD_PROPERTY@got_webrtc_revision@120644@@@",
-      "@@@SET_BUILD_PROPERTY@got_swarming_client_revision@276089@@@",
-      "@@@SET_BUILD_PROPERTY@got_v8_revision@43426@@@"
+      "@@@SET_BUILD_PROPERTY@got_swarming_client_revision@276089@@@"
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
       "\nimport shutil, sys, os\nshutil.rmtree(sys.argv[1], True)\nshutil.rmtree(sys.argv[2], True)\ntry:\n  os.remove(sys.argv[3])\nexcept OSError:\n  pass\nfor base, _dirs, files in os.walk(sys.argv[4]):\n  for f in files:\n    if f.endswith('.pyc'):\n      os.remove(os.path.join(base, f))\n",
       "[SLAVE_BUILD]/src/out/Release/debug_info_dumps",
       "[SLAVE_BUILD]/src/out/Release/test_logs",
       "[SLAVE_BUILD]/src/out/build_product.zip",
@@ skipping 80 matching lines @@
       "[BUILD]/scripts/slave/chromium/sizes.py",
       "--target",
       "Release",
       "--platform",
       "android-cronet"
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "sizes"
   }
 ]