chromium_tests: fix crash in deapply_patch on got_webkit_revision

scripts/slave/recipes/ozone_ecs.expected/trybot.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "[BUILD]/scripts/slave/bot_update.py",
       "--master",
       "chromium.testing.master",
       "--builder",
       "TestBuilder",
       "--slave",
       "TestSlavename",
       "--spec",
       "cache_dir = None\nsolutions = [{'custom_vars': {'googlecode_url': 'svn://svn-mirror.golo.chromium.org/%s', 'nacl_trunk': 'svn://svn-mirror.golo.chromium.org/native_client/trunk', 'sourceforge_url': 'svn://svn-mirror.golo.chromium.org/%(repo)s', 'webkit_trunk': 'svn://svn-mirror.golo.chromium.org/blink/trunk'}, 'deps_file': 'DEPS', 'managed': True, 'name': 'src', 'url': 'svn://svn-mirror.golo.chromium.org/chrome/trunk/src'}]",
       "--root",
       "src",
       "--revision_mapping_file",
-      "{\"src\": \"got_revision\", \"src/native_client\": \"got_nacl_revision\", \"src/third_party/WebKit\": \"got_webkit_revision\", \"src/third_party/webrtc\": \"got_webrtc_revision\", \"src/tools/swarming_client\": \"got_swarming_client_revision\", \"src/v8\": \"got_v8_revision\"}",
+      "{\"src\": \"got_revision\", \"src/native_client\": \"got_nacl_revision\", \"src/third_party/webrtc\": \"got_webrtc_revision\", \"src/tools/swarming_client\": \"got_swarming_client_revision\", \"src/v8\": \"got_v8_revision\"}",
       "--issue",
       "12853011",
       "--patchset",
       "1",
       "--rietveld_server",
       "https://codereview.chromium.org",
       "--output_json",
       "/path/to/tmp/json",
       "--revision",
       "src@HEAD"
@@ skipping 50 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_nacl_revision@274981@@@",
-      "@@@SET_BUILD_PROPERTY@got_webkit_revision@124383@@@",
-      "@@@SET_BUILD_PROPERTY@got_swarming_client_revision@276089@@@",
       "@@@SET_BUILD_PROPERTY@got_webrtc_revision@120644@@@",
       "@@@SET_BUILD_PROPERTY@got_revision@170242@@@",
-      "@@@SET_BUILD_PROPERTY@got_v8_revision@43426@@@"
+      "@@@SET_BUILD_PROPERTY@got_nacl_revision@274981@@@",
+      "@@@SET_BUILD_PROPERTY@got_v8_revision@43426@@@",
+      "@@@SET_BUILD_PROPERTY@got_swarming_client_revision@276089@@@"
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
       "[DEPOT_TOOLS]/apply_issue.py",
       "-r",
       "[SLAVE_BUILD]/src",
       "-i",
@@ skipping 622 matching lines @@
       "--step-name=url_unittests",
       "--builder-name=TestBuilder",
       "--slave-name=TestSlavename",
       "--build-number=571",
       "--no-spawn-dbus",
       "url_unittests"
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "url_unittests"
   }
-]
+]