Keep browser process alive while there are platform apps with background pages running.

chrome/browser/extensions/api/media_galleries_private/media_galleries_private_apitest.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 "base/stringprintf.h"
 #include "base/system_monitor/system_monitor.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/extensions/api/media_galleries_private/media_galleries_private_api.h"
 #include "chrome/browser/extensions/extension_apitest.h"
 #include "chrome/browser/extensions/extension_service.h"
@@ skipping 62 matching lines @@
   }
 
   void ChangeListener(content::RenderViewHost* host,
                       const std::string& js_command,
                       const std::string& ok_message) {
     ExtensionTestMessageListener listener(ok_message, false  /* no reply */);
     host->ExecuteJavascriptInWebFrame(string16(), ASCIIToUTF16(js_command));
     EXPECT_TRUE(listener.WaitUntilSatisfied());
   }
 
-  void AttachDetach() {
-    Attach();
-    Detach();
-  }
-
-  void Attach() {
+  void Attach(bool listening) {
+    const std::string expect_attach_msg =
+        base::StringPrintf("%s,%s", kAttachTestOk, kDeviceName);
+    ExtensionTestMessageListener attach_finished_listener(
+        expect_attach_msg,
+        false  /* no reply */);
     base::SystemMonitor::Get()->ProcessRemovableStorageAttached(
         device_id_, ASCIIToUTF16(kDeviceName), kDevicePath);
     WaitForDeviceEvents();
+    if (listening)
+      EXPECT_TRUE(attach_finished_listener.WaitUntilSatisfied());
   }
 
-  void Detach() {
+  void Detach(bool listening) {
+    ExtensionTestMessageListener detach_finished_listener(
+        kDetachTestOk,
+        false  /* no reply */);
     base::SystemMonitor::Get()->ProcessRemovableStorageDetached(device_id_);
     WaitForDeviceEvents();
+    if (listening)
+      EXPECT_TRUE(detach_finished_listener.WaitUntilSatisfied());
   }
 
  private:
   void WaitForDeviceEvents() {
     content::RunAllPendingInMessageLoop();
   }
 
   std::string device_id_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaGalleriesPrivateApiTest);
 };
 
 IN_PROC_BROWSER_TEST_F(MediaGalleriesPrivateApiTest, DeviceAttachDetachEvents) {
   // Setup.
   const extensions::Extension* extension =
       LoadExtension(test_data_dir_.AppendASCII(kTestExtensionPath));
   ASSERT_TRUE(extension);
 
   content::RenderViewHost* host =
       extensions::ExtensionSystem::Get(browser()->profile())->
           process_manager()->GetBackgroundHostForExtension(extension->id())->
               render_view_host();
   ASSERT_TRUE(host);
 
   // No listeners, attach and detach a couple times.
-  AttachDetach();
-  AttachDetach();
+  Attach(false);
+  Detach(false);
+  Attach(false);
+  Detach(false);
 
   // Add attach listener.
   ChangeListener(host, kAddAttachListenerCmd, kAddAttachListenerOk);
 
   // Attach / detach
-  const std::string expect_attach_msg =
-      base::StringPrintf("%s,%s", kAttachTestOk, kDeviceName);
-  ExtensionTestMessageListener attach_finished_listener(expect_attach_msg,
-                                                        false  /* no reply */);
-  Attach();
-  EXPECT_TRUE(attach_finished_listener.WaitUntilSatisfied());
-  Detach();
+  Attach(true);
+  Detach(false);
 
   // Attach / detach
-  Attach();
-  EXPECT_TRUE(attach_finished_listener.WaitUntilSatisfied());
-  // Detach
-  Detach();
+  Attach(true);
+  Detach(false);
 
   // Remove attach listener.
   ChangeListener(host, kRemoveAttachListenerCmd, kRemoveAttachListenerOk);
 
   // No listeners, attach and detach a couple times.
-  AttachDetach();
-  AttachDetach();
+  Attach(false);
+  Detach(false);
+  Attach(false);
+  Detach(false);
 
   // Add detach listener.
   ChangeListener(host, kAddDummyDetachListenerCmd, kAddDummyDetachListenerOk);
 
   // Attach / detach
-  Attach();
-
-  ExtensionTestMessageListener detach_finished_listener(kDetachTestOk,
-                                                        false  /* no reply */);
-  Detach();
-  EXPECT_TRUE(detach_finished_listener.WaitUntilSatisfied());
+  Attach(false);
+  Detach(true);
 
   // Attach / detach
-  Attach();
-  Detach();
-  EXPECT_TRUE(detach_finished_listener.WaitUntilSatisfied());
+  Attach(false);
+  Detach(true);
 
   // Switch ok dummy detach listener for the regular one.
   ChangeListener(host, kRemoveDummyDetachListenerCmd,
                  kRemoveDummyDetachListenerOk);
   ChangeListener(host, kAddDetachListenerCmd, kAddDetachListenerOk);
 
   // Add attach listener.
   ChangeListener(host, kAddAttachListenerCmd, kAddAttachListenerOk);
 
-  Attach();
-  EXPECT_TRUE(attach_finished_listener.WaitUntilSatisfied());
-  Detach();
-  EXPECT_TRUE(detach_finished_listener.WaitUntilSatisfied());
+  Attach(true);
+  Detach(true);
 
-  Attach();
-  EXPECT_TRUE(attach_finished_listener.WaitUntilSatisfied());
-  Detach();
-  EXPECT_TRUE(detach_finished_listener.WaitUntilSatisfied());
+  Attach(true);
+  Detach(true);
+  CloseShellWindowsAndWaitForAppToExit();
 }