Add ChromeBrowserMainExtraParts for non main parts. (take 3)

This was originally submitted as http://codereview.chromium.org/8539038/ which was reverted because of a failing test on win.

This reverts the code back to a single instance of BrowserMainParts, with auxillary parts (Gtk, Views, Aura, Touch) implemented from a new base class, ChromeBrowserParts, which has a Chrome specific interface, allowing initialization to be better subdivided.

This should fix the notifications auto tests.

This CL also addresses the test failure on win (and a test failure on linux_chromeos triggered by the windows fix).

BUG=103821
TEST=Make sure all tests and autotests run

TBR=jam@chromium.org

Review URL: http://codereview.chromium.org/8480032

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@110972 0039d316-1c4b-4281-b951-d872f2087c98

31 files changed, 379 insertions, 371 deletions

diff --git a/chrome/browser/chrome_browser_main.cc b/chrome/browser/chrome_browser_main.cc
index 8ba3c3ef..f8a5d8b 100644
--- a/chrome/browser/chrome_browser_main.cc
+++ b/chrome/browser/chrome_browser_main.cc
@@ -32,6 +32,7 @@
 #include "chrome/browser/background/background_mode_manager.h"
 #include "chrome/browser/browser_process_impl.h"
 #include "chrome/browser/browser_shutdown.h"
+#include "chrome/browser/chrome_browser_main_extra_parts.h"
 #include "chrome/browser/defaults.h"
 #include "chrome/browser/extensions/default_apps_trial.h"
 #include "chrome/browser/extensions/extension_protocols.h"
@@ -558,13 +559,6 @@ void OptionallyRunChromeOSLoginManager(const CommandLine& parsed_command_line,
   }
 }
 
-#else
-
-void OptionallyRunChromeOSLoginManager(const CommandLine& parsed_command_line,
-                                       Profile* profile) {
-  // Dummy empty function for non-ChromeOS builds to avoid extra ifdefs below.
-}
-
 #endif  // defined(OS_CHROMEOS)
 
 #if defined(OS_MACOSX)
@@ -685,6 +679,9 @@ ChromeBrowserMainParts::ChromeBrowserMainParts(
 }
 
 ChromeBrowserMainParts::~ChromeBrowserMainParts() {
+  for (int i = static_cast<int>(chrome_extra_parts_.size())-1; i >= 0; --i)
+    delete chrome_extra_parts_[i];
+  chrome_extra_parts_.clear();
 }
 
 // This will be called after the command-line has been mutated by about:flags
@@ -1166,23 +1163,38 @@ DLLEXPORT void __cdecl RelaunchChromeBrowserWithNewCommandLineIfNeeded() {
 }
 #endif
 
+// content::BrowserMainParts implementation ------------------------------------
+
 void ChromeBrowserMainParts::PreEarlyInitialization() {
+  for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
+    chrome_extra_parts_[i]->PreEarlyInitialization();
 }
 
 void ChromeBrowserMainParts::PostEarlyInitialization() {
+  for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
+    chrome_extra_parts_[i]->PostEarlyInitialization();
 }
 
 void ChromeBrowserMainParts::ToolkitInitialized() {
+  for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
+    chrome_extra_parts_[i]->ToolkitInitialized();
 }
 
 void ChromeBrowserMainParts::PreMainMessageLoopStart() {
+  for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
+    chrome_extra_parts_[i]->PreMainMessageLoopStart();
 }
 
 void ChromeBrowserMainParts::PostMainMessageLoopStart() {
+  for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
+    chrome_extra_parts_[i]->PostMainMessageLoopStart();
 }
 
 void ChromeBrowserMainParts::PreMainMessageLoopRun() {
   result_code_ = PreMainMessageLoopRunImpl();
+
+  for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
+    chrome_extra_parts_[i]->PreMainMessageLoopRun();
 }
 
 int ChromeBrowserMainParts::PreMainMessageLoopRunImpl() {
@@ -1496,6 +1508,10 @@ int ChromeBrowserMainParts::PreMainMessageLoopRunImpl() {
   SetBrowserX11ErrorHandlers();
 #endif
 
+  // Desktop construction occurs here, (required before profile creation).
+  for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
+    chrome_extra_parts_[i]->PostBrowserProcessInit();
+
   // Profile creation ----------------------------------------------------------
 
 #if defined(OS_CHROMEOS)
@@ -1561,6 +1577,11 @@ int ChromeBrowserMainParts::PreMainMessageLoopRunImpl() {
     g_browser_process->browser_policy_connector()->SetUserPolicyTokenService(
         profile_->GetTokenService());
   }
+
+  // Tests should be able to tune login manager before showing it.
+  // Thus only show login manager in normal (non-testing) mode.
+  if (!parameters().ui_task)
+    OptionallyRunChromeOSLoginManager(parsed_command_line(), profile_);
 #endif
 
 #if !defined(OS_MACOSX)
@@ -1609,6 +1630,11 @@ int ChromeBrowserMainParts::PreMainMessageLoopRunImpl() {
   }
 #endif
 
+  // TODO(stevenjb): Move ChromeOS login code into PostProfileInitialized().
+  // (Requires making ChromeBrowserMainPartsChromeos a non "main" Parts).
+  for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
+    chrome_extra_parts_[i]->PostProfileInitialized();
+
   // Show the First Run UI if this is the first time Chrome has been run on
   // this computer, or we're being compelled to do so by a command line flag.
   // Note that this be done _after_ the PrefService is initialized and all
@@ -1834,20 +1860,6 @@ int ChromeBrowserMainParts::PreMainMessageLoopRunImpl() {
   NaClProcessHost::EarlyStartup();
 #endif
 
-  run_message_loop_ = true;
-  return content::RESULT_CODE_NORMAL_EXIT;
-}
-
-// Called from MainMessageLoopRun().
-void ChromeBrowserMainParts::StartBrowserOrUITask() {
-  // Still initializing, so need to allow IO.
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
-
-  // Tests should be able to tune login manager before showing it.
-  // Thus only show login manager in normal (non-testing) mode.
-  if (!parameters().ui_task)
-    OptionallyRunChromeOSLoginManager(parsed_command_line(), profile_);
-
   if (parameters().ui_task) {
     // We are in test mode. Run one task and enter the main message loop.
 #if defined(OS_MACOSX)
@@ -1917,18 +1929,13 @@ void ChromeBrowserMainParts::StartBrowserOrUITask() {
     }
   }
   browser_init_.reset();
+  return result_code_;
 }
 
 bool ChromeBrowserMainParts::MainMessageLoopRun(int* result_code) {
   // Set the result code set in PreMainMessageLoopRun or set above.
   *result_code = result_code_;
 
-  // TODO(stevenjb): Move this to another phase, and/or clean up
-  // PreMainMessageLoopRun() so that this can happen after desktop
-  // initilaization and before running the main loop.
-  if (run_message_loop_)
-    StartBrowserOrUITask();
-
   if (!run_message_loop_)
     return true;  // Don't run the default message loop.
 
@@ -2050,8 +2057,19 @@ void ChromeBrowserMainParts::PostMainMessageLoopRun() {
   // to bypass this code.  Perhaps we need a *final* hook that is called on all
   // paths from content/browser/browser_main.
   CHECK(MetricsService::UmaMetricsProperlyShutdown());
+
+  for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
+    chrome_extra_parts_[i]->PostMainMessageLoopRun();
 }
 
+// Public members:
+
+void ChromeBrowserMainParts::AddParts(ChromeBrowserMainExtraParts* parts) {
+  chrome_extra_parts_.push_back(parts);
+}
+
+// Misc ------------------------------------------------------------------------
+
 // This code is specific to the Windows-only PreReadExperiment field-trial.
 void RecordPreReadExperimentTime(const char* name, base::TimeDelta time) {
   DCHECK(name != NULL);
diff --git a/chrome/browser/chrome_browser_main.h b/chrome/browser/chrome_browser_main.h
index 867b14c..806af87 100644
--- a/chrome/browser/chrome_browser_main.h
+++ b/chrome/browser/chrome_browser_main.h
@@ -9,6 +9,7 @@
 #include "base/basictypes.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/scoped_vector.h"
 #include "base/metrics/field_trial.h"
 #include "base/tracked_objects.h"
 #include "chrome/browser/first_run/first_run.h"
@@ -17,6 +18,7 @@
 
 class BrowserInit;
 class BrowserProcessImpl;
+class ChromeBrowserMainExtraParts;
 class FieldTrialSynchronizer;
 class HistogramSynchronizer;
 class MetricsService;
@@ -43,23 +45,14 @@ class ChromeBrowserMainParts : public content::BrowserMainParts {
  public:
   virtual ~ChromeBrowserMainParts();
 
-  // Constructs metrics service and does related initialization, including
-  // creation of field trials. Call only after labs have been converted to
-  // switches.
-  MetricsService* SetupMetricsAndFieldTrials(PrefService* local_state);
-
-  const content::MainFunctionParams& parameters() const {
-    return parameters_;
-  }
-  const CommandLine& parsed_command_line() const {
-    return parsed_command_line_;
-  }
+  // Add additional ChromeBrowserMainExtraParts.
+  virtual void AddParts(ChromeBrowserMainExtraParts* parts);
 
  protected:
   explicit ChromeBrowserMainParts(
       const content::MainFunctionParams& parameters);
 
-  // content::BrowserParts overrides
+  // content::BrowserMainParts overrides.
   virtual void PreEarlyInitialization() OVERRIDE;
   virtual void PostEarlyInitialization() OVERRIDE;
   virtual void ToolkitInitialized() OVERRIDE;
@@ -72,6 +65,15 @@ class ChromeBrowserMainParts : public content::BrowserMainParts {
   // Displays a warning message that we can't find any locale data files.
   virtual void ShowMissingLocaleMessageBox() = 0;
 
+  const content::MainFunctionParams& parameters() const {
+    return parameters_;
+  }
+  const CommandLine& parsed_command_line() const {
+    return parsed_command_line_;
+  }
+
+  Profile* profile() { return profile_; }
+
  private:
   // Methods for |EarlyInitialization()| ---------------------------------------
 
@@ -104,6 +106,11 @@ class ChromeBrowserMainParts : public content::BrowserMainParts {
 
   // Methods for |SetupMetricsAndFieldTrials()| --------------------------------
 
+  // Constructs metrics service and does related initialization, including
+  // creation of field trials. Call only after labs have been converted to
+  // switches.
+  MetricsService* SetupMetricsAndFieldTrials(PrefService* local_state);
+
   static MetricsService* InitializeMetrics(
       const CommandLine& parsed_command_line,
       const PrefService* local_state);
@@ -115,7 +122,6 @@ class ChromeBrowserMainParts : public content::BrowserMainParts {
   // Methods for Main Message Loop -------------------------------------------
 
   int PreMainMessageLoopRunImpl();
-  void StartBrowserOrUITask();
 
   // Members initialized on construction ---------------------------------------
 
@@ -137,6 +143,10 @@ class ChromeBrowserMainParts : public content::BrowserMainParts {
   // SetupMetricsAndFieldTrials is called.
   scoped_ptr<base::FieldTrialList> field_trial_list_;
 
+  // Vector of additional ChromeBrowserMainExtraParts.
+  // Parts are deleted in the inverse order they are added.
+  std::vector<ChromeBrowserMainExtraParts*> chrome_extra_parts_;
+
   // Members initialized after / released before main_message_loop_ ------------
 
   scoped_ptr<BrowserInit> browser_init_;
diff --git a/chrome/browser/chrome_browser_main_extra_parts.cc b/chrome/browser/chrome_browser_main_extra_parts.cc
new file mode 100644
index 0000000..3188931
--- /dev/null
+++ b/chrome/browser/chrome_browser_main_extra_parts.cc
@@ -0,0 +1,38 @@
+// Copyright (c) 2011 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/chrome_browser_main_extra_parts.h"
+
+ChromeBrowserMainExtraParts::ChromeBrowserMainExtraParts() {
+}
+
+ChromeBrowserMainExtraParts::~ChromeBrowserMainExtraParts() {
+}
+
+void ChromeBrowserMainExtraParts::PreEarlyInitialization() {
+}
+
+void ChromeBrowserMainExtraParts::PostEarlyInitialization() {
+}
+
+void ChromeBrowserMainExtraParts::PreMainMessageLoopStart() {
+}
+
+void ChromeBrowserMainExtraParts::PostMainMessageLoopStart() {
+}
+
+void ChromeBrowserMainExtraParts::ToolkitInitialized() {
+}
+
+void ChromeBrowserMainExtraParts::PostBrowserProcessInit() {
+}
+
+void ChromeBrowserMainExtraParts::PostProfileInitialized() {
+}
+
+void ChromeBrowserMainExtraParts::PreMainMessageLoopRun() {
+}
+
+void ChromeBrowserMainExtraParts::PostMainMessageLoopRun() {
+}
diff --git a/chrome/browser/chrome_browser_main_extra_parts.h b/chrome/browser/chrome_browser_main_extra_parts.h
new file mode 100644
index 0000000..a839d44
--- /dev/null
+++ b/chrome/browser/chrome_browser_main_extra_parts.h
@@ -0,0 +1,44 @@
+// Copyright (c) 2011 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.
+
+#ifndef CHROME_BROWSER_CHROME_BROWSER_MAIN_EXTRA_PARTS_H_
+#define CHROME_BROWSER_CHROME_BROWSER_MAIN_EXTRA_PARTS_H_
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+
+// Interface class for Parts owned by ChromeBrowserMainParts.
+// The default implementation for all methods is empty.
+
+// Most of these map to content::BrowserMainParts methods. This interface is
+// separate to allow stages to be further subdivided for Chrome specific
+// initialization stages (e.g. browser process init, profile init).
+
+class ChromeBrowserMainExtraParts {
+ public:
+  ChromeBrowserMainExtraParts();
+  virtual ~ChromeBrowserMainExtraParts();
+
+  // EarlyInitialization methods.
+  virtual void PreEarlyInitialization();
+  virtual void PostEarlyInitialization();
+
+  // PreMainMessageLoopStart methods.
+  virtual void PreMainMessageLoopStart();
+  virtual void PostMainMessageLoopStart();
+
+  // ToolkitInitialized methods.
+  virtual void ToolkitInitialized();
+
+  // MainMessageLoopRun methods.
+  virtual void PostBrowserProcessInit();
+  virtual void PostProfileInitialized();
+  virtual void PreMainMessageLoopRun();
+  virtual void PostMainMessageLoopRun();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ChromeBrowserMainExtraParts);
+};
+
+#endif  // CHROME_BROWSER_CHROME_BROWSER_MAIN_EXTRA_PARTS_H_
diff --git a/chrome/browser/chrome_browser_parts_aura.cc b/chrome/browser/chrome_browser_main_extra_parts_aura.cc
index a2907e1..ea5214f 100644
--- a/chrome/browser/chrome_browser_parts_aura.cc
+++ b/chrome/browser/chrome_browser_main_extra_parts_aura.cc
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "chrome/browser/chrome_browser_parts_aura.h"
+#include "chrome/browser/chrome_browser_main_extra_parts_aura.h"
 #include "chrome/browser/ui/views/aura/chrome_shell_delegate.h"
 #include "ui/aura/desktop.h"
 #include "ui/aura_shell/shell.h"
@@ -11,26 +11,11 @@
 #include "chrome/browser/chromeos/system/runtime_environment.h"
 #endif
 
-ChromeBrowserPartsAura::ChromeBrowserPartsAura()
-    : content::BrowserMainParts() {
+ChromeBrowserMainExtraPartsAura::ChromeBrowserMainExtraPartsAura()
+    : ChromeBrowserMainExtraParts() {
 }
 
-void ChromeBrowserPartsAura::PreEarlyInitialization() {
-}
-
-void ChromeBrowserPartsAura::PostEarlyInitialization() {
-}
-
-void ChromeBrowserPartsAura::ToolkitInitialized() {
-}
-
-void ChromeBrowserPartsAura::PreMainMessageLoopStart() {
-}
-
-void ChromeBrowserPartsAura::PostMainMessageLoopStart() {
-}
-
-void ChromeBrowserPartsAura::PreMainMessageLoopRun() {
+void ChromeBrowserMainExtraPartsAura::PostBrowserProcessInit() {
 #if defined(OS_CHROMEOS)
   if (chromeos::system::runtime_environment::IsRunningOnChromeOS())
     aura::Desktop::set_use_fullscreen_host_window(true);
@@ -39,10 +24,3 @@ void ChromeBrowserPartsAura::PreMainMessageLoopRun() {
   // Shell takes ownership of ChromeShellDelegate.
   aura_shell::Shell::CreateInstance(new ChromeShellDelegate);
 }
-
-bool ChromeBrowserPartsAura::MainMessageLoopRun(int* result_code) {
-  return false;
-}
-
-void ChromeBrowserPartsAura::PostMainMessageLoopRun() {
-}
diff --git a/chrome/browser/chrome_browser_main_extra_parts_aura.h b/chrome/browser/chrome_browser_main_extra_parts_aura.h
new file mode 100644
index 0000000..2af4a18
--- /dev/null
+++ b/chrome/browser/chrome_browser_main_extra_parts_aura.h
@@ -0,0 +1,22 @@
+// Copyright (c) 2011 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.
+
+#ifndef CHROME_BROWSER_CHROME_BROWSER_MAIN_EXTRA_PARTS_AURA_H_
+#define CHROME_BROWSER_CHROME_BROWSER_MAIN_EXTRA_PARTS_AURA_H_
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "chrome/browser/chrome_browser_main_extra_parts.h"
+
+class ChromeBrowserMainExtraPartsAura : public ChromeBrowserMainExtraParts {
+ public:
+  ChromeBrowserMainExtraPartsAura();
+
+  virtual void PostBrowserProcessInit() OVERRIDE;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ChromeBrowserMainExtraPartsAura);
+};
+
+#endif  // CHROME_BROWSER_CHROME_BROWSER_MAIN_EXTRA_PARTS_AURA_H_
diff --git a/chrome/browser/chrome_browser_parts_gtk.cc b/chrome/browser/chrome_browser_main_extra_parts_gtk.cc
index 3d1a5aa..406d3ec 100644
--- a/chrome/browser/chrome_browser_parts_gtk.cc
+++ b/chrome/browser/chrome_browser_main_extra_parts_gtk.cc
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "chrome/browser/chrome_browser_parts_gtk.h"
+#include "chrome/browser/chrome_browser_main_extra_parts_gtk.h"
 
 #include <gtk/gtk.h>
 
@@ -14,37 +14,16 @@
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/gtk_util.h"
 
-ChromeBrowserPartsGtk::ChromeBrowserPartsGtk()
-    : content::BrowserMainParts() {
+ChromeBrowserMainExtraPartsGtk::ChromeBrowserMainExtraPartsGtk()
+    : ChromeBrowserMainExtraParts() {
 }
 
-void ChromeBrowserPartsGtk::PreEarlyInitialization() {
+void ChromeBrowserMainExtraPartsGtk::PreEarlyInitialization() {
   DetectRunningAsRoot();
 }
 
-void ChromeBrowserPartsGtk::PostEarlyInitialization() {
-}
-
-void ChromeBrowserPartsGtk::ToolkitInitialized() {
-}
-
-void ChromeBrowserPartsGtk::PreMainMessageLoopStart() {
-}
-
-void ChromeBrowserPartsGtk::PostMainMessageLoopStart() {
-}
-
-void ChromeBrowserPartsGtk::PreMainMessageLoopRun() {
-}
-
-bool ChromeBrowserPartsGtk::MainMessageLoopRun(int* result_code) {
-  return false;
-}
-
-void ChromeBrowserPartsGtk::PostMainMessageLoopRun() {
-}
 
-void ChromeBrowserPartsGtk::DetectRunningAsRoot() {
+void ChromeBrowserMainExtraPartsGtk::DetectRunningAsRoot() {
   if (geteuid() == 0) {
     const CommandLine& command_line = *CommandLine::ForCurrentProcess();
     if (command_line.HasSwitch(switches::kUserDataDir))
@@ -86,7 +65,7 @@ void ChromeBrowserPartsGtk::DetectRunningAsRoot() {
 }
 
 // static
-void ChromeBrowserPartsGtk::ShowMessageBox(const char* message) {
+void ChromeBrowserMainExtraPartsGtk::ShowMessageBox(const char* message) {
   GtkWidget* dialog = gtk_message_dialog_new(
       NULL,
       static_cast<GtkDialogFlags>(0),
diff --git a/chrome/browser/chrome_browser_main_extra_parts_gtk.h b/chrome/browser/chrome_browser_main_extra_parts_gtk.h
new file mode 100644
index 0000000..34b596f
--- /dev/null
+++ b/chrome/browser/chrome_browser_main_extra_parts_gtk.h
@@ -0,0 +1,26 @@
+// Copyright (c) 2011 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.
+
+// Contains functions used by BrowserMain() that are gtk-specific.
+
+#ifndef CHROME_BROWSER_CHROME_BROWSER_MAIN_EXTRA_PARTS_GTK_H_
+#define CHROME_BROWSER_CHROME_BROWSER_MAIN_EXTRA_PARTS_GTK_H_
+#pragma once
+
+#include "base/compiler_specific.h"
+#include "chrome/browser/chrome_browser_main_extra_parts.h"
+
+class ChromeBrowserMainExtraPartsGtk : public ChromeBrowserMainExtraParts {
+ public:
+  ChromeBrowserMainExtraPartsGtk();
+
+  virtual void PreEarlyInitialization() OVERRIDE;
+
+  static void ShowMessageBox(const char* message);
+
+ private:
+  void DetectRunningAsRoot();
+};
+
+#endif  // CHROME_BROWSER_CHROME_BROWSER_MAIN_EXTRA_PARTS_GTK_H_
diff --git a/chrome/browser/chrome_browser_parts_touch.cc b/chrome/browser/chrome_browser_main_extra_parts_touch.cc
index 506cf1d..bfaa919 100644
--- a/chrome/browser/chrome_browser_parts_touch.cc
+++ b/chrome/browser/chrome_browser_main_extra_parts_touch.cc
@@ -2,19 +2,15 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "chrome/browser/chrome_browser_parts_touch.h"
+#include "chrome/browser/chrome_browser_main_extra_parts_touch.h"
 
 #include "chrome/browser/ui/touch/sensors/screen_orientation_listener.h"
 
-ChromeBrowserPartsTouch::ChromeBrowserPartsTouch()
-    : content::BrowserMainParts() {
+ChromeBrowserMainExtraPartsTouch::ChromeBrowserMainExtraPartsTouch()
+    : ChromeBrowserMainExtraParts() {
 }
 
-void ChromeBrowserPartsTouch::PreMainMessageLoopRun() {
+void ChromeBrowserMainExtraPartsTouch::PreMainMessageLoopRun() {
   // Make sure the singleton ScreenOrientationListener object is created.
   ScreenOrientationListener::GetInstance();
 }
-
-bool ChromeBrowserPartsTouch::MainMessageLoopRun(int* result_code) {
-  return false;
-}
diff --git a/chrome/browser/chrome_browser_main_extra_parts_touch.h b/chrome/browser/chrome_browser_main_extra_parts_touch.h
new file mode 100644
index 0000000..603a750
--- /dev/null
+++ b/chrome/browser/chrome_browser_main_extra_parts_touch.h
@@ -0,0 +1,22 @@
+// Copyright (c) 2011 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.
+
+#ifndef CHROME_BROWSER_CHROME_BROWSER_MAIN_EXTRA_PARTS_TOUCH_H_
+#define CHROME_BROWSER_CHROME_BROWSER_MAIN_EXTRA_PARTS_TOUCH_H_
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "chrome/browser/chrome_browser_main_extra_parts.h"
+
+class ChromeBrowserMainExtraPartsTouch : public ChromeBrowserMainExtraParts {
+ public:
+  ChromeBrowserMainExtraPartsTouch();
+
+  virtual void PreMainMessageLoopRun() OVERRIDE;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ChromeBrowserMainExtraPartsTouch);
+};
+
+#endif  // CHROME_BROWSER_CHROME_BROWSER_MAIN_EXTRA_PARTS_TOUCH_H_
diff --git a/chrome/browser/chrome_browser_parts_views.cc b/chrome/browser/chrome_browser_main_extra_parts_views.cc
index 328eb7c..af505df 100644
--- a/chrome/browser/chrome_browser_parts_views.cc
+++ b/chrome/browser/chrome_browser_main_extra_parts_views.cc
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "chrome/browser/chrome_browser_parts_views.h"
+#include "chrome/browser/chrome_browser_main_extra_parts_views.h"
 
 #include <string>
 
@@ -11,11 +11,11 @@
 #include "chrome/common/chrome_switches.h"
 #include "views/widget/widget.h"
 
-ChromeBrowserPartsViews::ChromeBrowserPartsViews()
-    : content::BrowserMainParts() {
+ChromeBrowserMainExtraPartsViews::ChromeBrowserMainExtraPartsViews()
+    : ChromeBrowserMainExtraParts() {
 }
 
-void ChromeBrowserPartsViews::ToolkitInitialized() {
+void ChromeBrowserMainExtraPartsViews::ToolkitInitialized() {
   // The delegate needs to be set before any UI is created so that windows
   // display the correct icon.
   if (!views::ViewsDelegate::views_delegate)
@@ -25,10 +25,3 @@ void ChromeBrowserPartsViews::ToolkitInitialized() {
   if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kDebugViewsPaint))
     views::Widget::SetDebugPaintEnabled(true);
 }
-
-void ChromeBrowserPartsViews::PreMainMessageLoopRun() {
-}
-
-bool ChromeBrowserPartsViews::MainMessageLoopRun(int* result_code) {
-  return false;
-}
diff --git a/chrome/browser/chrome_browser_main_extra_parts_views.h b/chrome/browser/chrome_browser_main_extra_parts_views.h
new file mode 100644
index 0000000..6ac14c7
--- /dev/null
+++ b/chrome/browser/chrome_browser_main_extra_parts_views.h
@@ -0,0 +1,21 @@
+// Copyright (c) 2011 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.
+
+// Contains functions used by BrowserMain() that are views-specific.
+
+#ifndef CHROME_BROWSER_CHROME_BROWSER_MAIN_EXTRA_PARTS_VIEWS_H_
+#define CHROME_BROWSER_CHROME_BROWSER_MAIN_EXTRA_PARTS_VIEWS_H_
+#pragma once
+
+#include "base/compiler_specific.h"
+#include "chrome/browser/chrome_browser_main_extra_parts.h"
+
+class ChromeBrowserMainExtraPartsViews : public ChromeBrowserMainExtraParts {
+ public:
+  ChromeBrowserMainExtraPartsViews();
+
+  virtual void ToolkitInitialized() OVERRIDE;
+};
+
+#endif  // CHROME_BROWSER_CHROME_BROWSER_MAIN_EXTRA_PARTS_VIEWS_H_
diff --git a/chrome/browser/chrome_browser_main_linux.cc b/chrome/browser/chrome_browser_main_linux.cc
index 9abc2ca..4900de6 100644
--- a/chrome/browser/chrome_browser_main_linux.cc
+++ b/chrome/browser/chrome_browser_main_linux.cc
@@ -5,7 +5,7 @@
 #include "chrome/browser/chrome_browser_main_linux.h"
 
 #if defined(TOOLKIT_USES_GTK)
-#include "chrome/browser/chrome_browser_parts_gtk.h"
+#include "chrome/browser/chrome_browser_main_extra_parts_gtk.h"
 #endif
 
 ChromeBrowserMainPartsLinux::ChromeBrowserMainPartsLinux(
@@ -18,7 +18,7 @@ void ChromeBrowserMainPartsLinux::ShowMissingLocaleMessageBox() {
   // This should never happen on Aura.
   NOTREACHED() << chrome_browser::kMissingLocaleDataMessage;
 #elif defined(TOOLKIT_USES_GTK)
-  ChromeBrowserPartsGtk::ShowMessageBox(
+  ChromeBrowserMainExtraPartsGtk::ShowMessageBox(
       chrome_browser::kMissingLocaleDataMessage);
 #else
 #error "Need MessageBox implementation for linux without Aura or Gtk"
diff --git a/chrome/browser/chrome_browser_main_unittest.cc b/chrome/browser/chrome_browser_main_unittest.cc
index 4a2f265..f5c549b 100644
--- a/chrome/browser/chrome_browser_main_unittest.cc
+++ b/chrome/browser/chrome_browser_main_unittest.cc
@@ -30,12 +30,9 @@ TEST_F(BrowserMainTest, WarmConnectionFieldTrial_WarmestSocket) {
 
   scoped_ptr<content::MainFunctionParams> params(
       new content::MainFunctionParams(command_line_));
-  ScopedVector<content::BrowserMainParts> bwv;
-  content::GetContentClient()->browser()->CreateBrowserMainParts(
-      *params, &(bwv.get()));
-  ChromeBrowserMainParts* cbw = NULL;
-  if (bwv.size() >= 1)
-    cbw = static_cast<ChromeBrowserMainParts*>(bwv[0]);
+  scoped_ptr<content::BrowserMainParts> bw(
+      content::GetContentClient()->browser()->CreateBrowserMainParts(*params));
+  ChromeBrowserMainParts* cbw = static_cast<ChromeBrowserMainParts*>(bw.get());
   EXPECT_TRUE(cbw);
   if (cbw) {
     cbw->WarmConnectionFieldTrial();
@@ -46,12 +43,9 @@ TEST_F(BrowserMainTest, WarmConnectionFieldTrial_WarmestSocket) {
 TEST_F(BrowserMainTest, WarmConnectionFieldTrial_Random) {
   scoped_ptr<content::MainFunctionParams> params(
       new content::MainFunctionParams(command_line_));
-  ScopedVector<content::BrowserMainParts> bwv;
-  content::GetContentClient()->browser()->CreateBrowserMainParts(
-      *params, &(bwv.get()));
-  ChromeBrowserMainParts* cbw = NULL;
-  if (bwv.size() >= 1)
-    cbw = static_cast<ChromeBrowserMainParts*>(bwv[0]);
+  scoped_ptr<content::BrowserMainParts> bw(
+      content::GetContentClient()->browser()->CreateBrowserMainParts(*params));
+  ChromeBrowserMainParts* cbw = static_cast<ChromeBrowserMainParts*>(bw.get());
   EXPECT_TRUE(cbw);
   if (cbw) {
     const int kNumRuns = 1000;
@@ -71,17 +65,15 @@ TEST_F(BrowserMainTest, WarmConnectionFieldTrial_Invalid) {
       new content::MainFunctionParams(command_line_));
   // This test ends up launching a new process, and that doesn't initialize the
   // ContentClient interfaces.
-  ScopedVector<content::BrowserMainParts> bwv;
+  scoped_ptr<content::BrowserMainParts> bw;
   if (content::GetContentClient()) {
-    content::GetContentClient()->browser()->CreateBrowserMainParts(
-        *params, &(bwv.get()));
+    bw.reset(content::GetContentClient()->browser()->CreateBrowserMainParts(
+        *params));
   } else {
     chrome::ChromeContentBrowserClient ccbc;
-    ccbc.CreateBrowserMainParts(*params, &(bwv.get()));
+    bw.reset(ccbc.CreateBrowserMainParts(*params));
   }
-  ChromeBrowserMainParts* cbw = NULL;
-  if (bwv.size() >= 1)
-    cbw = static_cast<ChromeBrowserMainParts*>(bwv[0]);
+  ChromeBrowserMainParts* cbw = static_cast<ChromeBrowserMainParts*>(bw.get());
   EXPECT_TRUE(cbw);
   if (cbw) {
 #if defined(NDEBUG) && defined(DCHECK_ALWAYS_ON)
diff --git a/chrome/browser/chrome_browser_parts_aura.h b/chrome/browser/chrome_browser_parts_aura.h
deleted file mode 100644
index dbc9d76..0000000
--- a/chrome/browser/chrome_browser_parts_aura.h
+++ /dev/null
@@ -1,29 +0,0 @@
-// Copyright (c) 2011 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.
-
-#ifndef CHROME_BROWSER_CHROME_BROWSER_PARTS_AURA_H_
-#define CHROME_BROWSER_CHROME_BROWSER_PARTS_AURA_H_
-
-#include "base/basictypes.h"
-#include "base/compiler_specific.h"
-#include "content/public/browser/browser_main_parts.h"
-
-class ChromeBrowserPartsAura : public content::BrowserMainParts {
- public:
-  ChromeBrowserPartsAura();
-
-  virtual void PreEarlyInitialization() OVERRIDE;
-  virtual void PostEarlyInitialization() OVERRIDE;
-  virtual void ToolkitInitialized() OVERRIDE;
-  virtual void PreMainMessageLoopStart() OVERRIDE;
-  virtual void PostMainMessageLoopStart() OVERRIDE;
-  virtual void PreMainMessageLoopRun() OVERRIDE;
-  virtual bool MainMessageLoopRun(int* result_code) OVERRIDE;
-  virtual void PostMainMessageLoopRun() OVERRIDE;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(ChromeBrowserPartsAura);
-};
-
-#endif  // CHROME_BROWSER_CHROME_BROWSER_PARTS_AURA_H_
diff --git a/chrome/browser/chrome_browser_parts_gtk.h b/chrome/browser/chrome_browser_parts_gtk.h
deleted file mode 100644
index e824f3c..0000000
--- a/chrome/browser/chrome_browser_parts_gtk.h
+++ /dev/null
@@ -1,33 +0,0 @@
-// Copyright (c) 2011 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.
-
-// Contains functions used by BrowserMain() that are gtk-specific.
-
-#ifndef CHROME_BROWSER_CHROME_BROWSER_PARTS_GTK_H_
-#define CHROME_BROWSER_CHROME_BROWSER_PARTS_GTK_H_
-#pragma once
-
-#include "base/compiler_specific.h"
-#include "content/public/browser/browser_main_parts.h"
-
-class ChromeBrowserPartsGtk : public content::BrowserMainParts {
- public:
-  ChromeBrowserPartsGtk();
-
-  virtual void PreEarlyInitialization() OVERRIDE;
-  virtual void PostEarlyInitialization() OVERRIDE;
-  virtual void ToolkitInitialized() OVERRIDE;
-  virtual void PreMainMessageLoopStart() OVERRIDE;
-  virtual void PostMainMessageLoopStart() OVERRIDE;
-  virtual void PreMainMessageLoopRun() OVERRIDE;
-  virtual bool MainMessageLoopRun(int* result_code) OVERRIDE;
-  virtual void PostMainMessageLoopRun() OVERRIDE;
-
-  static void ShowMessageBox(const char* message);
-
- private:
-  void DetectRunningAsRoot();
-};
-
-#endif  // CHROME_BROWSER_CHROME_BROWSER_PARTS_GTK_H_
diff --git a/chrome/browser/chrome_browser_parts_touch.h b/chrome/browser/chrome_browser_parts_touch.h
deleted file mode 100644
index 0cd9502..0000000
--- a/chrome/browser/chrome_browser_parts_touch.h
+++ /dev/null
@@ -1,29 +0,0 @@
-// Copyright (c) 2011 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.
-
-#ifndef CHROME_BROWSER_CHROME_BROWSER_PARTS_TOUCH_H_
-#define CHROME_BROWSER_CHROME_BROWSER_PARTS_TOUCH_H_
-
-#include "base/basictypes.h"
-#include "base/compiler_specific.h"
-#include "content/public/browser/browser_main_parts.h"
-
-class ChromeBrowserPartsTouch : public content::BrowserMainParts {
- public:
-  ChromeBrowserPartsTouch();
-
-  virtual void PreEarlyInitialization() OVERRIDE {}
-  virtual void PostEarlyInitialization() OVERRIDE {}
-  virtual void PreMainMessageLoopStart() OVERRIDE {}
-  virtual void ToolkitInitialized() OVERRIDE {}
-  virtual void PostMainMessageLoopStart() OVERRIDE {}
-  virtual void PreMainMessageLoopRun() OVERRIDE;
-  virtual bool MainMessageLoopRun(int* result_code) OVERRIDE;
-  virtual void PostMainMessageLoopRun() OVERRIDE {}
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(ChromeBrowserPartsTouch);
-};
-
-#endif  // CHROME_BROWSER_CHROME_BROWSER_PARTS_TOUCH_H_
diff --git a/chrome/browser/chrome_browser_parts_views.h b/chrome/browser/chrome_browser_parts_views.h
deleted file mode 100644
index e3805dc..0000000
--- a/chrome/browser/chrome_browser_parts_views.h
+++ /dev/null
@@ -1,28 +0,0 @@
-// Copyright (c) 2011 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.
-
-// Contains functions used by BrowserMain() that are views-specific.
-
-#ifndef CHROME_BROWSER_CHROME_BROWSER_PARTS_VIEWS_H_
-#define CHROME_BROWSER_CHROME_BROWSER_PARTS_VIEWS_H_
-#pragma once
-
-#include "base/compiler_specific.h"
-#include "content/public/browser/browser_main_parts.h"
-
-class ChromeBrowserPartsViews : public content::BrowserMainParts {
- public:
-  ChromeBrowserPartsViews();
-
-  virtual void PreEarlyInitialization() OVERRIDE {}
-  virtual void PostEarlyInitialization() OVERRIDE {}
-  virtual void PreMainMessageLoopStart() OVERRIDE {}
-  virtual void ToolkitInitialized() OVERRIDE;
-  virtual void PostMainMessageLoopStart() OVERRIDE {}
-  virtual void PreMainMessageLoopRun() OVERRIDE;
-  virtual bool MainMessageLoopRun(int* result_code) OVERRIDE;
-  virtual void PostMainMessageLoopRun() OVERRIDE {}
-};
-
-#endif  // CHROME_BROWSER_CHROME_BROWSER_PARTS_VIEWS_H_
diff --git a/chrome/browser/chrome_content_browser_client.cc b/chrome/browser/chrome_content_browser_client.cc
index 018acf5..62fe5b0 100644
--- a/chrome/browser/chrome_content_browser_client.cc
+++ b/chrome/browser/chrome_content_browser_client.cc
@@ -93,15 +93,19 @@
 #endif
 
 #if defined(TOOLKIT_USES_GTK)
-#include "chrome/browser/chrome_browser_parts_gtk.h"
+#include "chrome/browser/chrome_browser_main_extra_parts_gtk.h"
 #endif
 
 #if defined(TOOLKIT_VIEWS)
-#include "chrome/browser/chrome_browser_parts_views.h"
+#include "chrome/browser/chrome_browser_main_extra_parts_views.h"
 #endif
 
 #if defined(USE_AURA)
-#include "chrome/browser/chrome_browser_parts_aura.h"
+#include "chrome/browser/chrome_browser_main_extra_parts_aura.h"
+#endif
+
+#if defined(TOUCH_UI)
+#include "chrome/browser/chrome_browser_main_extra_parts_touch.h"
 #endif
 
 #if defined(OS_LINUX) || defined(OS_OPENBSD)
@@ -109,10 +113,6 @@
 #include "chrome/browser/crash_handler_host_linux.h"
 #endif
 
-#if defined(TOUCH_UI)
-#include "chrome/browser/chrome_browser_parts_touch.h"
-#endif
-
 #if defined(TOOLKIT_VIEWS)
 #include "chrome/browser/ui/views/tab_contents/tab_contents_view_views.h"
 #elif defined(TOOLKIT_USES_GTK)
@@ -216,43 +216,44 @@ RenderProcessHostPrivilege GetProcessPrivilege(
 
 namespace chrome {
 
-void ChromeContentBrowserClient::CreateBrowserMainParts(
-    const content::MainFunctionParams& parameters,
-    std::vector<content::BrowserMainParts*>* parts_list) {
+content::BrowserMainParts* ChromeContentBrowserClient::CreateBrowserMainParts(
+    const content::MainFunctionParams& parameters) {
+  ChromeBrowserMainParts* main_parts;
   // Construct the Main browser parts based on the OS type.
 #if defined(OS_WIN)
-  parts_list->push_back(new ChromeBrowserMainPartsWin(parameters));
+  main_parts = new ChromeBrowserMainPartsWin(parameters);
 #elif defined(OS_MACOSX)
-  parts_list->push_back(new ChromeBrowserMainPartsMac(parameters));
+  main_parts = new ChromeBrowserMainPartsMac(parameters);
 #elif defined(OS_CHROMEOS)
-  parts_list->push_back(new ChromeBrowserMainPartsChromeos(parameters));
+  main_parts = new ChromeBrowserMainPartsChromeos(parameters);
 #elif defined(OS_LINUX) || defined(OS_OPENBSD)
-  parts_list->push_back(new ChromeBrowserMainPartsLinux(parameters));
+  main_parts = new ChromeBrowserMainPartsLinux(parameters);
 #elif defined(OS_POSIX)
-  parts_list->push_back(new ChromeBrowserMainPartsPosix(parameters));
+  main_parts = new ChromeBrowserMainPartsPosix(parameters);
 #else
   NOTREACHED();
-  parts_list->push_back(new ChromeBrowserMainParts(parameters));
+  main_parts = new ChromeBrowserMainParts(parameters);
 #endif
 
   // Construct additional browser parts. Stages are called in the order in
   // which they are added.
 #if defined(TOOLKIT_USES_GTK)
-  parts_list->push_back(new ChromeBrowserPartsGtk());
+  main_parts->AddParts(new ChromeBrowserMainExtraPartsGtk());
 #endif
 
 #if defined(TOOLKIT_VIEWS)
-  parts_list->push_back(new ChromeBrowserPartsViews());
+  main_parts->AddParts(new ChromeBrowserMainExtraPartsViews());
 #endif
 
 #if defined(USE_AURA)
-  parts_list->push_back(new ChromeBrowserPartsAura());
+  main_parts->AddParts(new ChromeBrowserMainExtraPartsAura());
 #endif
 
 #if defined(TOUCH_UI)
-  parts_list->push_back(new ChromeBrowserPartsTouch());
+  main_parts->AddParts(new ChromeBrowserMainExtraPartsTouch());
 #endif
 
+  return main_parts;
 }
 
 RenderWidgetHostView* ChromeContentBrowserClient::CreateViewForWidget(
diff --git a/chrome/browser/chrome_content_browser_client.h b/chrome/browser/chrome_content_browser_client.h
index c91e658..e174d4d 100644
--- a/chrome/browser/chrome_content_browser_client.h
+++ b/chrome/browser/chrome_content_browser_client.h
@@ -15,9 +15,8 @@ namespace chrome {
 
 class ChromeContentBrowserClient : public content::ContentBrowserClient {
  public:
-  virtual void CreateBrowserMainParts(
-      const content::MainFunctionParams& parameters,
-      std::vector<content::BrowserMainParts*>* parts_list) OVERRIDE;
+  virtual content::BrowserMainParts* CreateBrowserMainParts(
+      const content::MainFunctionParams& parameters) OVERRIDE;
   virtual RenderWidgetHostView* CreateViewForWidget(
       RenderWidgetHost* widget) OVERRIDE;
   virtual TabContentsView* CreateTabContentsView(
diff --git a/chrome/browser/chromeos/chrome_browser_main_chromeos.cc b/chrome/browser/chromeos/chrome_browser_main_chromeos.cc
index 8c39e33..5b737ac 100644
--- a/chrome/browser/chromeos/chrome_browser_main_chromeos.cc
+++ b/chrome/browser/chromeos/chrome_browser_main_chromeos.cc
@@ -87,32 +87,10 @@ ChromeBrowserMainPartsChromeos::ChromeBrowserMainPartsChromeos(
 }
 
 ChromeBrowserMainPartsChromeos::~ChromeBrowserMainPartsChromeos() {
-  // Shutdown the upgrade detector for Chrome OS. The upgrade detector
-  // stops monitoring changes from the update engine.
-  if (UpgradeDetectorChromeos::GetInstance())
-    UpgradeDetectorChromeos::GetInstance()->Shutdown();
-
-  // Shutdown the network change notifier for Chrome OS. The network
-  // change notifier stops monitoring changes from the power manager and
-  // the network manager.
-  if (chromeos::CrosNetworkChangeNotifierFactory::GetInstance())
-    chromeos::CrosNetworkChangeNotifierFactory::GetInstance()->Shutdown();
-
   chromeos::disks::DiskMountManager::Shutdown();
 
   chromeos::BluetoothManager::Shutdown();
 
-  // We should remove observers attached to D-Bus clients before
-  // DBusThreadManager is shut down.
-  if (session_manager_observer_.get()) {
-    chromeos::DBusThreadManager::Get()->GetSessionManagerClient()->
-        RemoveObserver(session_manager_observer_.get());
-  }
-  if (brightness_observer_.get()) {
-    chromeos::DBusThreadManager::Get()->GetPowerManagerClient()
-        ->RemoveObserver(brightness_observer_.get());
-  }
-
   chromeos::DBusThreadManager::Shutdown();
 
   if (!parameters().ui_task && chromeos::CrosLibrary::Get())
@@ -169,7 +147,7 @@ void ChromeBrowserMainPartsChromeos::PreMainMessageLoopRun() {
 }
 
 void ChromeBrowserMainPartsChromeos::PostMainMessageLoopStart() {
-  ChromeBrowserMainPartsPosix::PostMainMessageLoopStart();
+  ChromeBrowserMainPartsLinux::PostMainMessageLoopStart();
   MessageLoopForUI* message_loop = MessageLoopForUI::current();
   message_loop->AddObserver(g_message_loop_observer.Pointer());
 
@@ -212,3 +190,30 @@ void ChromeBrowserMainPartsChromeos::PostMainMessageLoopStart() {
 #endif
   }
 }
+
+// Shut down services before the browser process, etc are destroyed.
+void ChromeBrowserMainPartsChromeos::PostMainMessageLoopRun() {
+  ChromeBrowserMainPartsLinux::PostMainMessageLoopRun();
+
+  // Shutdown the upgrade detector for Chrome OS. The upgrade detector
+  // stops monitoring changes from the update engine.
+  if (UpgradeDetectorChromeos::GetInstance())
+    UpgradeDetectorChromeos::GetInstance()->Shutdown();
+
+  // Shutdown the network change notifier for Chrome OS. The network
+  // change notifier stops monitoring changes from the power manager and
+  // the network manager.
+  if (chromeos::CrosNetworkChangeNotifierFactory::GetInstance())
+    chromeos::CrosNetworkChangeNotifierFactory::GetInstance()->Shutdown();
+
+  // We should remove observers attached to D-Bus clients before
+  // DBusThreadManager is shut down.
+  if (session_manager_observer_.get()) {
+    chromeos::DBusThreadManager::Get()->GetSessionManagerClient()->
+        RemoveObserver(session_manager_observer_.get());
+  }
+  if (brightness_observer_.get()) {
+    chromeos::DBusThreadManager::Get()->GetPowerManagerClient()
+        ->RemoveObserver(brightness_observer_.get());
+  }
+}
diff --git a/chrome/browser/chromeos/chrome_browser_main_chromeos.h b/chrome/browser/chromeos/chrome_browser_main_chromeos.h
index ddd17be..449d9fa 100644
--- a/chrome/browser/chromeos/chrome_browser_main_chromeos.h
+++ b/chrome/browser/chromeos/chrome_browser_main_chromeos.h
@@ -23,10 +23,12 @@ class ChromeBrowserMainPartsChromeos : public ChromeBrowserMainPartsLinux {
       const content::MainFunctionParams& parameters);
   virtual ~ChromeBrowserMainPartsChromeos();
 
+  // content::BrowserMainParts overrides.
   virtual void PreEarlyInitialization() OVERRIDE;
   virtual void PreMainMessageLoopStart() OVERRIDE;
-  virtual void PreMainMessageLoopRun() OVERRIDE;
   virtual void PostMainMessageLoopStart() OVERRIDE;
+  virtual void PreMainMessageLoopRun() OVERRIDE;
+  virtual void PostMainMessageLoopRun() OVERRIDE;
 
  private:
   scoped_ptr<chromeos::BrightnessObserver> brightness_observer_;
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index 9e8ebdb..06c7a9f 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -355,14 +355,16 @@
         'browser/chrome_browser_main_win.h',
         'browser/chrome_browser_main_x11.cc',
         'browser/chrome_browser_main_x11.h',
-        'browser/chrome_browser_parts_aura.cc',
-        'browser/chrome_browser_parts_aura.h',
-        'browser/chrome_browser_parts_gtk.cc',
-        'browser/chrome_browser_parts_gtk.h',
-        'browser/chrome_browser_parts_touch.cc',
-        'browser/chrome_browser_parts_touch.h',
-        'browser/chrome_browser_parts_views.cc',
-        'browser/chrome_browser_parts_views.h',
+        'browser/chrome_browser_main_extra_parts.cc',
+        'browser/chrome_browser_main_extra_parts.h',
+        'browser/chrome_browser_main_extra_parts_aura.cc',
+        'browser/chrome_browser_main_extra_parts_aura.h',
+        'browser/chrome_browser_main_extra_parts_gtk.cc',
+        'browser/chrome_browser_main_extra_parts_gtk.h',
+        'browser/chrome_browser_main_extra_parts_touch.cc',
+        'browser/chrome_browser_main_extra_parts_touch.h',
+        'browser/chrome_browser_main_extra_parts_views.cc',
+        'browser/chrome_browser_main_extra_parts_views.h',
         'browser/chrome_content_browser_client.cc',
         'browser/chrome_content_browser_client.h',
         'browser/chrome_plugin_message_filter.cc',
diff --git a/content/browser/browser_main_loop.cc b/content/browser/browser_main_loop.cc
index 2059d2a..dd93e58 100644
--- a/content/browser/browser_main_loop.cc
+++ b/content/browser/browser_main_loop.cc
@@ -158,26 +158,21 @@ BrowserMainLoop::BrowserMainLoop(const content::MainFunctionParams& parameters)
 }
 
 BrowserMainLoop::~BrowserMainLoop() {
-  // Destroy added parts in reverse order.
-  for (int i = static_cast<int>(parts_list_.size())-1; i >= 0; --i)
-    delete parts_list_[i];
-  parts_list_.clear();
-
 #if defined(OS_WIN)
   OleUninitialize();
 #endif
 }
 
 void BrowserMainLoop::Init() {
-  GetContentClient()->browser()->CreateBrowserMainParts(
-      parameters_, &parts_list_);
+  parts_.reset(
+      GetContentClient()->browser()->CreateBrowserMainParts(parameters_));
 }
 
 // BrowserMainLoop stages ==================================================
 
 void BrowserMainLoop::EarlyInitialization() {
-  for (size_t i = 0; i < parts_list_.size(); ++i)
-    parts_list_[i]->PreEarlyInitialization();
+  if (parts_.get())
+    parts_->PreEarlyInitialization();
 
 #if defined(OS_WIN)
   net::EnsureWinsockInit();
@@ -223,13 +218,13 @@ void BrowserMainLoop::EarlyInitialization() {
   if (parsed_command_line_.HasSwitch(switches::kEnableTcpFastOpen))
     net::set_tcp_fastopen_enabled(true);
 
-  for (size_t i = 0; i < parts_list_.size(); ++i)
-    parts_list_[i]->PostEarlyInitialization();
+  if (parts_.get())
+    parts_->PostEarlyInitialization();
 }
 
 void BrowserMainLoop::MainMessageLoopStart() {
-  for (size_t i = 0; i < parts_list_.size(); ++i)
-    parts_list_[i]->PreMainMessageLoopStart();
+  if (parts_.get())
+    parts_->PreMainMessageLoopStart();
 
 #if defined(OS_WIN)
   // If we're running tests (ui_task is non-null), then the ResourceBundle
@@ -260,31 +255,24 @@ void BrowserMainLoop::MainMessageLoopStart() {
   system_message_window_.reset(new SystemMessageWindowWin);
 #endif
 
-  for (size_t i = 0; i < parts_list_.size(); ++i)
-    parts_list_[i]->PostMainMessageLoopStart();
+  if (parts_.get())
+    parts_->PostMainMessageLoopStart();
 }
 
 void BrowserMainLoop::RunMainMessageLoopParts(
     bool* completed_main_message_loop) {
-  for (size_t i = 0; i < parts_list_.size(); ++i)
-    parts_list_[i]->PreMainMessageLoopRun();
+  if (parts_.get())
+    parts_->PreMainMessageLoopRun();
 
   TRACE_EVENT_BEGIN_ETW("BrowserMain:MESSAGE_LOOP", 0, "");
   // If the UI thread blocks, the whole UI is unresponsive.
   // Do not allow disk IO from the UI thread.
   base::ThreadRestrictions::SetIOAllowed(false);
 
-  // Iterate through each of the parts. If any of them ran the main
-  // message loop then they should return |true|. Otherwise
-  // BrowserMainLoop::MainMessageLoopRun loop will be run.
   bool ran_main_loop = false;
-  for (size_t i = 0; i < parts_list_.size(); ++i) {
-    int result_code = result_code_;
-    if (parts_list_[i]->MainMessageLoopRun(&result_code)) {
-      ran_main_loop = true;
-      result_code_ = result_code;
-    }
-  }
+  if (parts_.get())
+    ran_main_loop = parts_->MainMessageLoopRun(&result_code_);
+
   if (!ran_main_loop)
     MainMessageLoopRun();
 
@@ -293,8 +281,8 @@ void BrowserMainLoop::RunMainMessageLoopParts(
   if (completed_main_message_loop)
     *completed_main_message_loop = true;
 
-  for (size_t i = 0; i < parts_list_.size(); ++i)
-    parts_list_[i]->PostMainMessageLoopRun();
+  if (parts_.get())
+    parts_->PostMainMessageLoopRun();
 }
 
 void BrowserMainLoop::InitializeMainThread() {
@@ -343,8 +331,8 @@ void BrowserMainLoop::InitializeToolkit() {
     LOG_GETLASTERROR(FATAL);
 #endif
 
-  for (size_t i = 0; i < parts_list_.size(); ++i)
-    parts_list_[i]->ToolkitInitialized();
+  if (parts_.get())
+    parts_->ToolkitInitialized();
 }
 
 void BrowserMainLoop::MainMessageLoopRun() {
diff --git a/content/browser/browser_main_loop.h b/content/browser/browser_main_loop.h
index 0abe7e1..d02d578 100644
--- a/content/browser/browser_main_loop.h
+++ b/content/browser/browser_main_loop.h
@@ -6,8 +6,6 @@
 #define CONTENT_BROWSER_BROWSER_MAIN_LOOP_H_
 #pragma once
 
-#include <vector>
-
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 
@@ -55,11 +53,6 @@ class BrowserMainLoop {
   const CommandLine& parsed_command_line_;
   int result_code_;
 
-  // Vector of BrowserMainParts set by CreateBrowserMainParts ------------------
-  // The BrowserParts fucntions for each part are called in the order added.
-  // They are released (destroyed) in the reverse order.
-  std::vector<BrowserMainParts*> parts_list_;
-
   // Members initialized in |MainMessageLoopStart()| ---------------------------
   scoped_ptr<MessageLoop> main_message_loop_;
   scoped_ptr<base::SystemMonitor> system_monitor_;
@@ -68,6 +61,13 @@ class BrowserMainLoop {
 #if defined(OS_WIN)
   scoped_ptr<SystemMessageWindowWin> system_message_window_;
 #endif
+
+  // Destroy parts_ before main_message_loop_ (required) and before other
+  // classes constructed in content (but after main_thread_).
+  scoped_ptr<BrowserMainParts> parts_;
+
+  // Members initialized in |InitializeMainThread()| ---------------------------
+  // This must get destroyed before other threads that are created in parts_.
   scoped_ptr<BrowserThreadImpl> main_thread_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserMainLoop);
diff --git a/content/browser/mock_content_browser_client.cc b/content/browser/mock_content_browser_client.cc
index b2c2dd6..5b1c08b 100644
--- a/content/browser/mock_content_browser_client.cc
+++ b/content/browser/mock_content_browser_client.cc
@@ -23,9 +23,9 @@ MockContentBrowserClient::MockContentBrowserClient() {
 MockContentBrowserClient::~MockContentBrowserClient() {
 }
 
-void MockContentBrowserClient::CreateBrowserMainParts(
-    const content::MainFunctionParams& parameters,
-    std::vector<BrowserMainParts*>* parts_list) {
+BrowserMainParts* MockContentBrowserClient::CreateBrowserMainParts(
+    const content::MainFunctionParams& parameters) {
+  return NULL;
 }
 
 RenderWidgetHostView* MockContentBrowserClient::CreateViewForWidget(
diff --git a/content/browser/mock_content_browser_client.h b/content/browser/mock_content_browser_client.h
index 56a7be2..2b61f71 100644
--- a/content/browser/mock_content_browser_client.h
+++ b/content/browser/mock_content_browser_client.h
@@ -21,9 +21,8 @@ class MockContentBrowserClient : public ContentBrowserClient {
   MockContentBrowserClient();
   virtual ~MockContentBrowserClient();
 
-  virtual void CreateBrowserMainParts(
-      const content::MainFunctionParams& parameters,
-      std::vector<BrowserMainParts*>* parts_list) OVERRIDE;
+  virtual BrowserMainParts* CreateBrowserMainParts(
+      const content::MainFunctionParams& parameters) OVERRIDE;
   virtual RenderWidgetHostView* CreateViewForWidget(
       RenderWidgetHost* widget) OVERRIDE;
   virtual TabContentsView* CreateTabContentsView(
diff --git a/content/public/browser/browser_main_parts.h b/content/public/browser/browser_main_parts.h
index 0bbaa83..860541c 100644
--- a/content/public/browser/browser_main_parts.h
+++ b/content/public/browser/browser_main_parts.h
@@ -15,9 +15,8 @@ namespace content {
 // Each stage is represented by a single BrowserMainParts method, called from
 // the corresponding method in |BrowserMainLoop| (e.g., EarlyInitialization())
 // which does the following:
-//  - calls a method (e.g., "PreEarlyInitialization()") for each member of
-//    |parts_|. Parts will implement platform or tookit specific code for that
-//    stage.
+//  - calls a method (e.g., "PreEarlyInitialization()") which implements
+//    platform / tookit specific code for that stage.
 //  - calls various methods for things common to all platforms (for that stage).
 //  - calls a method (e.g., "PostEarlyInitialization()") for platform-specific
 //    code to be called after the common code.
@@ -49,9 +48,6 @@ namespace content {
 //    existing chunk which makes it longer than one or two lines, please move
 //    the code out into a separate method.)
 //
-// There can be any number of "Parts". These should be constructed in
-// ContentBrowserClient::CreateBrowserMainParts. Each stage will be called
-// for each part in the order it was added. Destruction is in the inverse order.
 class CONTENT_EXPORT BrowserMainParts {
  public:
   BrowserMainParts() {}
@@ -63,17 +59,16 @@ class CONTENT_EXPORT BrowserMainParts {
 
   virtual void PreMainMessageLoopStart() = 0;
 
+  virtual void PostMainMessageLoopStart() = 0;
+
   // Allows an embedder to do any extra toolkit initialization.
   virtual void ToolkitInitialized() = 0;
 
-  virtual void PostMainMessageLoopStart() = 0;
-
   virtual void PreMainMessageLoopRun() = 0;
 
   // Returns true if the message loop was run, false otherwise.
+  // If this returns false, the default implementation will be run.
   // May set |result_code|, which will be returned by |BrowserMain()|.
-  // If no BrowserMainParts implementations return true, the default
-  // implementation will be run.
   virtual bool MainMessageLoopRun(int* result_code) = 0;
 
   virtual void PostMainMessageLoopRun() = 0;
diff --git a/content/public/browser/content_browser_client.h b/content/public/browser/content_browser_client.h
index 2a2a9f7..7d5438e 100644
--- a/content/public/browser/content_browser_client.h
+++ b/content/public/browser/content_browser_client.h
@@ -85,9 +85,8 @@ class ContentBrowserClient {
   // Allows the embedder to set any number of custom BrowserMainParts
   // implementations for the browser startup code. See comments in
   // browser_main_parts.h.
-  virtual void CreateBrowserMainParts(
-      const content::MainFunctionParams& parameters,
-      std::vector<BrowserMainParts*>* parts_list) = 0;
+  virtual BrowserMainParts* CreateBrowserMainParts(
+      const content::MainFunctionParams& parameters) = 0;
 
   // Platform-specific creator. Use this to construct new RenderWidgetHostViews
   // rather than using RenderWidgetHostViewWin & friends.
diff --git a/content/shell/shell_content_browser_client.cc b/content/shell/shell_content_browser_client.cc
index ec25de5..394af26 100644
--- a/content/shell/shell_content_browser_client.cc
+++ b/content/shell/shell_content_browser_client.cc
@@ -28,10 +28,9 @@ ShellContentBrowserClient::ShellContentBrowserClient()
 ShellContentBrowserClient::~ShellContentBrowserClient() {
 }
 
-void ShellContentBrowserClient::CreateBrowserMainParts(
-    const content::MainFunctionParams& parameters,
-    std::vector<BrowserMainParts*>* parts_list) {
-  parts_list->push_back(new ShellBrowserMainParts(parameters));
+BrowserMainParts* ShellContentBrowserClient::CreateBrowserMainParts(
+    const content::MainFunctionParams& parameters) {
+  return new ShellBrowserMainParts(parameters);
 }
 
 RenderWidgetHostView* ShellContentBrowserClient::CreateViewForWidget(
diff --git a/content/shell/shell_content_browser_client.h b/content/shell/shell_content_browser_client.h
index 1231ae0..4d0ac37 100644
--- a/content/shell/shell_content_browser_client.h
+++ b/content/shell/shell_content_browser_client.h
@@ -33,9 +33,8 @@ class ShellContentBrowserClient : public ContentBrowserClient
     shell_browser_main_parts_ = parts;
   }
 
-  virtual void CreateBrowserMainParts(
-      const content::MainFunctionParams& parameters,
-      std::vector<BrowserMainParts*>* parts_list) OVERRIDE;
+  virtual BrowserMainParts* CreateBrowserMainParts(
+      const content::MainFunctionParams& parameters) OVERRIDE;
   virtual RenderWidgetHostView* CreateViewForWidget(
       RenderWidgetHost* widget) OVERRIDE;
   virtual TabContentsView* CreateTabContentsView(