Enable by default threaded compositing on windows and FCM on mac

chrome/browser/task_manager/task_manager_browsertest.cc

 // Copyright (c) 2012 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/task_manager/task_manager.h"
 
 #include "base/file_path.h"
 #include "base/stringprintf.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/api/infobars/confirm_infobar_delegate.h"
@@ skipping 49 matching lines @@
 
 class TaskManagerBrowserTest : public ExtensionBrowserTest {
  public:
   TaskManagerModel* model() const {
     return TaskManager::GetInstance()->model();
   }
  protected:
   virtual void SetUpCommandLine(CommandLine* command_line) OVERRIDE {
     ExtensionBrowserTest::SetUpCommandLine(command_line);
 
-    // Do not prelaunch the GPU process for these tests because it will show
-    // up in task manager but whether it appears before or after the new tab
-    // renderer process is not well defined.
+    // Do not prelaunch the GPU process and disable accelerated compositing
+    // for these tests as the GPU process will show up in task manager but
+    // whether it appears before or after the new tab renderer process is not
+    // well defined.
     command_line->AppendSwitch(switches::kDisableGpuProcessPrelaunch);
+    command_line->AppendSwitch(switches::kDisableAcceleratedCompositing);
   }
 };
 
 #if defined(OS_MACOSX) || defined(OS_LINUX)
 #define MAYBE_ShutdownWhileOpen DISABLED_ShutdownWhileOpen
 #else
 #define MAYBE_ShutdownWhileOpen ShutdownWhileOpen
 #endif
 
 // Regression test for http://crbug.com/13361
@@ skipping 469 matching lines @@
   TaskManagerBrowserTestUtil::WaitForWebResourceChange(2);
 
   // Check that we get some value for the cache columns.
   DCHECK_NE(model()->GetResourceWebCoreImageCacheSize(resource_count),
             l10n_util::GetStringUTF16(IDS_TASK_MANAGER_NA_CELL_TEXT));
   DCHECK_NE(model()->GetResourceWebCoreScriptsCacheSize(resource_count),
             l10n_util::GetStringUTF16(IDS_TASK_MANAGER_NA_CELL_TEXT));
   DCHECK_NE(model()->GetResourceWebCoreCSSCacheSize(resource_count),
             l10n_util::GetStringUTF16(IDS_TASK_MANAGER_NA_CELL_TEXT));
 }