Revert "compositor-worker: Share a thread and an isolate for compositor workers."

Source/modules/InitModules.cpp

Index: Source/modules/InitModules.cpp
diff --git a/Source/modules/InitModules.cpp b/Source/modules/InitModules.cpp
index 6c18b364384254291e897cb486e685cb820c4254..1cfa4148a3228f97f24be8da134577da668228f6 100644
--- a/Source/modules/InitModules.cpp
+++ b/Source/modules/InitModules.cpp
@@ -13,7 +13,6 @@
 #include "modules/EventTargetModulesNames.h"
 #include "modules/IndexedDBNames.h"
 #include "modules/accessibility/AXObjectCacheImpl.h"
-#include "modules/compositorworker/CompositorWorkerManager.h"
 #include "modules/filesystem/DraggedIsolatedFileSystemImpl.h"
 #include "modules/webdatabase/DatabaseManager.h"
 
@@ -34,16 +33,11 @@ void ModulesInitializer::init()
 
     CoreInitializer::init();
 
-    if (RuntimeEnabledFeatures::compositorWorkerEnabled())
-        CompositorWorkerManager::initialize();
-
     ASSERT(isInitialized());
 }
 
 void ModulesInitializer::terminateThreads()
 {
-    if (RuntimeEnabledFeatures::compositorWorkerEnabled())
-        CompositorWorkerManager::shutdown();
     DatabaseManager::terminateDatabaseThread();
 }