compositor-worker: Keep worker backing thread alive for the lifetime of the compositor thread.

third_party/WebKit/Source/modules/compositorworker/CompositorWorker.cpp

Index: third_party/WebKit/Source/modules/compositorworker/CompositorWorker.cpp
diff --git a/third_party/WebKit/Source/modules/compositorworker/CompositorWorker.cpp b/third_party/WebKit/Source/modules/compositorworker/CompositorWorker.cpp
index 3eefc6ac2809d657c9ed86b7a22aaaa1ff712249..2799a29b7df8de79d098f7b49f7e6cee8497106a 100644
--- a/third_party/WebKit/Source/modules/compositorworker/CompositorWorker.cpp
+++ b/third_party/WebKit/Source/modules/compositorworker/CompositorWorker.cpp
@@ -10,6 +10,7 @@
 #include "core/workers/WorkerClients.h"
 #include "modules/EventTargetModules.h"
 #include "modules/compositorworker/CompositorWorkerMessagingProxy.h"
+#include "modules/compositorworker/CompositorWorkerThread.h"
 
 namespace blink {
 
@@ -27,6 +28,12 @@ CompositorWorker* CompositorWorker::create(ExecutionContext* context, const Stri
         return nullptr;
     }
     CompositorWorker* worker = new CompositorWorker(context);
+
+    // Ensure the compositor worker backing thread is ready before we try to
+    // initialize the CompositorWorker so that we can construct oilpan
+    // objects on the compositor thread referenced from the worker clients.
+    CompositorWorkerThread::ensureSharedBackingThread();
+
     if (worker->initialize(context, url, exceptionState))
         return worker;
     return nullptr;