Clear the custom element's reaction queue if upgrade fails.

third_party/WebKit/Source/core/BUILD.gn

 # 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.
 
 import("//build/config/chromecast_build.gni")
 import("//build/toolchain/toolchain.gni")
 import("//build/config/ui.gni")
 import("//build/split_static_library.gni")
 import("//testing/libfuzzer/fuzzer_test.gni")
 import("//third_party/WebKit/Source/bindings/bindings.gni")
@@ skipping 1044 matching lines @@
     "dom/RangeTest.cpp",
     "dom/ScriptRunnerTest.cpp",
     "dom/SelectorQueryTest.cpp",
     "dom/StaticRangeTest.cpp",
     "dom/StyleElementTest.cpp",
     "dom/StyleEngineTest.cpp",
     "dom/TextTest.cpp",
     "dom/TreeScopeStyleSheetCollectionTest.cpp",
     "dom/TreeScopeTest.cpp",
     "dom/URLSearchParamsTest.cpp",
+    "dom/custom/CustomElementDefinitionTest.cpp",
     "dom/custom/CustomElementDescriptorTest.cpp",
     "dom/custom/CustomElementReactionQueueTest.cpp",
     "dom/custom/CustomElementReactionStackTest.cpp",
     "dom/custom/CustomElementReactionTestHelpers.h",
     "dom/custom/CustomElementRegistryTest.cpp",
     "dom/custom/CustomElementTest.cpp",
     "dom/custom/CustomElementTestHelpers.cpp",
     "dom/custom/CustomElementTestHelpers.h",
     "dom/custom/CustomElementUpgradeSorterTest.cpp",
     "dom/shadow/FlatTreeTraversalTest.cpp",
@@ skipping 227 matching lines @@
   sources = [
     "html/parser/HTMLPreloadScannerFuzzer.cpp",
     "html/parser/TextResourceDecoderForFuzzing.h",
   ]
   seed_corpus = "//third_party/WebKit/LayoutTests/fast/parser"
   deps = [
     ":core",
     "../platform:blink_fuzzer_test_support",
   ]
 }