Add WebThread in AudioDestination to support AudioWorkletThread

third_party/WebKit/Source/platform/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/features.gni")
 import("//build/config/ui.gni")
 import("//testing/libfuzzer/fuzzer_test.gni")
 import("//testing/test.gni")
 import("//third_party/WebKit/public/public_features.gni")
 import("//third_party/WebKit/Source/build/scripts/scripts.gni")
@@ skipping 2144 matching lines @@
     "graphics/ImageDecodingStoreTest.cpp",
     "graphics/ImageFrameGeneratorTest.cpp",
     "graphics/ImageLayerChromiumTest.cpp",
     "graphics/gpu/DrawingBufferSoftwareRenderingTest.cpp",
     "graphics/test/FakeGLES2Interface.h",
     "graphics/test/FakeWebGraphicsContext3DProvider.h",
     "graphics/test/MockImageDecoder.h",
 
     # TODO(toyoshim): Remove Platform dependency and move to loader/BUILD.gn
     "loader/fetch/ResourceResponseTest.cpp",
+
+    # TODO(hongchan): Platform::Current()->CreateThread() returns nullptr
+    # without adding the test file into this section. Remove platform dependency
+    # when creating a valid thread becomes possible in the Blink unit test.
+    "audio/PushPullFIFOMultithreadTest.cpp",
   ]
 
   configs += [
     ":blink_platform_pch",
     "//third_party/WebKit/Source:config",
     "//third_party/WebKit/Source:inside_blink",
   ]
 
   deps = [
     ":test_support",
     "//testing/gmock",
     "//testing/gtest",
   ]
 }