Disable a test that is causing valgrind problems.

chrome/worker/worker_uitest.cc

 // Copyright (c) 2009 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.
 
 #include "chrome/browser/worker_host/worker_service.h"
 #include "chrome/test/automation/browser_proxy.h"
 #include "chrome/test/automation/tab_proxy.h"
 #include "chrome/test/ui/ui_layout_test.h"
 
 static const char kTestCompleteCookie[] = "status";
@@ skipping 19 matching lines @@
 TEST_F(WorkerTest, SingleWorker) {
   RunTest(L"single_worker.html");
 }
 
 TEST_F(WorkerTest, MultipleWorkers) {
   RunTest(L"multi_worker.html");
 }
 
 // WorkerFastLayoutTests works on the linux try servers, but fails on the
 // build bots.
-#if defined(OS_LINUX)
+#if !defined(OS_WIN)
 #define WorkerFastLayoutTests DISABLED_WorkerFastLayoutTests
 #endif
 
 TEST_F(WorkerTest, WorkerFastLayoutTests) {
   static const char* kLayoutTestFiles[] = {
     "stress-js-execution.html",
 #if defined(OS_WIN)
     // Workers don't properly initialize the V8 stack guard.
     // (http://code.google.com/p/chromium/issues/detail?id=21653).
     "use-machine-stack.html",
@@ skipping 175 matching lines @@
             UITest::GetBrowserProcessCount());
 
   // Now close the first tab and check that the queued workers were started.
   tab->Close(true);
   tab->NavigateToURL(GetTestUrl(L"google", L"google.html"));
 
   EXPECT_EQ(total_workers + 1 + (UITest::in_process_renderer() ? 0 : tab_count),
             UITest::GetBrowserProcessCount());
 }
 #endif