Introduce WorkerBackingThread

third_party/WebKit/Source/modules/ModulesInitializer.cpp

Index: third_party/WebKit/Source/modules/ModulesInitializer.cpp
diff --git a/third_party/WebKit/Source/modules/ModulesInitializer.cpp b/third_party/WebKit/Source/modules/ModulesInitializer.cpp
index 4377ca9c4b826b8b2a74ef1581433cddcba872aa..c20f0b016d38fb252b90875543ea81ccf52db095 100644
--- a/third_party/WebKit/Source/modules/ModulesInitializer.cpp
+++ b/third_party/WebKit/Source/modules/ModulesInitializer.cpp
@@ -14,6 +14,7 @@
 #include "modules/IndexedDBNames.h"
 #include "modules/accessibility/AXObjectCacheImpl.h"
 #include "modules/canvas2d/CanvasRenderingContext2D.h"
+#include "modules/compositorworker/CompositorWorkerThread.h"
 #include "modules/filesystem/DraggedIsolatedFileSystemImpl.h"
 #include "modules/imagebitmap/ImageBitmapRenderingContext.h"
 #include "modules/offscreencanvas/OffscreenCanvas.h"
@@ -60,6 +61,7 @@ void ModulesInitializer::shutdown()
 {
     ASSERT(isInitialized());
     DatabaseManager::terminateDatabaseThread();
+    CompositorWorkerThread::clearSharedBackingThread();
     CoreInitializer::shutdown();
 }