Enable device discovery notifications.

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/files/file_path.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/browser_process.h"
@@ skipping 86 matching lines @@
  protected:
   virtual void SetUpCommandLine(CommandLine* command_line) OVERRIDE {
     ExtensionBrowserTest::SetUpCommandLine(command_line);
 
     // 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);
+
+    // Do not launch device discovery process.
+    command_line->AppendSwitch(switches::kDisableDeviceDiscoveryNotifications);
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(TaskManagerBrowserTest);
 };
 
 #if defined(OS_MACOSX) || defined(OS_LINUX)
 #define MAYBE_ShutdownWhileOpen DISABLED_ShutdownWhileOpen
 #else
 #define MAYBE_ShutdownWhileOpen ShutdownWhileOpen
@@ skipping 384 matching lines @@
   DevToolsWindow* dev_tools = DevToolsWindow::ToggleDevToolsWindow(
       model()->GetResourceWebContents(1)->GetRenderViewHost(),
       true,
       DEVTOOLS_TOGGLE_ACTION_INSPECT);
   // Dock side bottom should be the default.
   ASSERT_EQ(DEVTOOLS_DOCK_SIDE_BOTTOM, dev_tools->dock_side());
   TaskManagerBrowserTestUtil::WaitForWebResourceChange(2);
 }
 
 #endif