Limit the safe point scope in WorkerThreadableLoader to the actual safe point.

clientBridgePtr->run() can allocate and is therefore not part of the
safe point.

TBR=haraken@chromium.org, vegorov@chromium.org
NOTRY=true
BUG=356307

Review URL: https://codereview.chromium.org/212573005

git-svn-id: svn://svn.chromium.org/blink/trunk@170058 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/loader/WorkerThreadableLoader.cpp

@@ -82,11 +82,13 @@ void WorkerThreadableLoader::loadResourceSynchronously(WorkerGlobalScope* worker
 
     RefPtr<WorkerThreadableLoader> loader = WorkerThreadableLoader::create(workerGlobalScope, clientWrapper, clientBridge.release(), request, options);
 
-    ThreadState::SafePointScope scope(ThreadState::HeapPointersOnStack);
-    blink::WebWaitableEvent* signalled = blink::Platform::current()->waitMultipleEvents(events);
-    if (signalled == shutdownEvent) {
-        loader->cancel();
-        return;
+    {
+        ThreadState::SafePointScope scope(ThreadState::HeapPointersOnStack);
+        blink::WebWaitableEvent* signalled = blink::Platform::current()->waitMultipleEvents(events);
+        if (signalled == shutdownEvent) {
+            loader->cancel();
+            return;
+        }
     }
 
     clientBridgePtr->run();