Extract locking behaviour from ProcessSingleton.

chrome/browser/first_run/try_chrome_dialog_view.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/first_run/try_chrome_dialog_view.h"
 
 #include <shellapi.h>
 
 #include "base/logging.h"
 #include "base/message_loop.h"
@@ skipping 37 matching lines @@
   BT_DONT_BUG_RADIO
 };
 
 const int kRadioGroupID = 1;
 
 }  // namespace
 
 // static
 TryChromeDialogView::Result TryChromeDialogView::Show(
     size_t flavor,
-    ProcessSingleton* process_singleton) {
+    const ActiveModalDialogListener& listener) {
   if (flavor > 10000) {
     // This is a test value. We want to make sure we exercise
     // returning this early. See TryChromeDialogBrowserTest test.
     return NOT_NOW;
   }
   TryChromeDialogView dialog(flavor);
-  return dialog.ShowModal(process_singleton);
+  return dialog.ShowModal(listener);
 }
 
 TryChromeDialogView::TryChromeDialogView(size_t flavor)
     : flavor_(flavor),
       popup_(NULL),
       try_chrome_(NULL),
       kill_chrome_(NULL),
       dont_try_chrome_(NULL),
       make_default_(NULL),
       result_(COUNT)  {
 }
 
 TryChromeDialogView::~TryChromeDialogView() {
 }
 
 TryChromeDialogView::Result TryChromeDialogView::ShowModal(
-    ProcessSingleton* process_singleton) {
+    const ActiveModalDialogListener& listener) {
   ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
 
   views::ImageView* icon = new views::ImageView();
   icon->SetImage(rb.GetNativeImageNamed(IDR_PRODUCT_LOGO_32).ToImageSkia());
   gfx::Size icon_size = icon->GetPreferredSize();
 
   popup_ = new views::Widget;
   if (!popup_) {
     NOTREACHED();
     return DIALOG_ERROR;
@@ skipping 195 matching lines @@
   // Carve the toast shape into the window.
   HWND toast_window;
 #if defined(USE_AURA)
   toast_window =
       popup_->GetNativeView()->GetRootWindow()->GetAcceleratedWidget();
 #else
   toast_window = popup_->GetNativeView();
 #endif
   SetToastRegion(toast_window, preferred.width(), preferred.height());
 
-  // Time to show the window in a modal loop. The ProcessSingleton should
-  // already be locked and it will not process WM_COPYDATA requests. Change the
-  // window to bring to foreground if a request arrives.
-  CHECK(process_singleton->locked());
-  process_singleton->SetForegroundWindow(popup_->GetNativeView());
+  // Time to show the window in a modal loop.
   popup_->Show();
+  if (!listener.is_null())
+    listener.Run(popup_->GetNativeView());
   MessageLoop::current()->Run();

[gab, 2013/03/27 18:03:26]

We shouldn't run the MessageLoop before the end of PreMainMessageLoopRun (and
this seems to be called before that... i.e., right after PreProfileInit()).

Would there be a way to CHECK if the MessageLoop is ever ran while the
process_singleton is locked? We could then fix all instances of this paradigm
and prevent further introductions of it.

[erikwright (departed), 2013/03/28 03:16:34]

I'm sure a way could be found to do that, but keep in mind that, at the moment,
that would be a bad thing to do because there is existing code that does run the
message loop before the end of PreMainMessageLoopRun.

Note that this is another advantage of the SequencedTaskRunner API. It doesn't
expose Run(), so by eliminating the global static MessageLoop::current() you
would prevent people from calling MessageLoop::Run when you don't want them to.

-  process_singleton->SetForegroundWindow(NULL);
+  if (!listener.is_null())
+    listener.Run(NULL);
   return result_;
 }
 
 gfx::Rect TryChromeDialogView::ComputeWindowPosition(int width,
                                                      int height,
                                                      bool is_RTL) {
   // The 'Shell_TrayWnd' is the taskbar. We like to show our window in that
   // monitor if we can. This code works even if such window is not found.
   HWND taskbar = ::FindWindowW(L"Shell_TrayWnd", NULL);
   HMONITOR monitor = ::MonitorFromWindow(taskbar, MONITOR_DEFAULTTOPRIMARY);
@@ skipping 56 matching lines @@
         result_ = TRY_CHROME_AS_DEFAULT;
   }
 
   popup_->Close();
   MessageLoop::current()->Quit();
 }
 
 void TryChromeDialogView::LinkClicked(views::Link* source, int event_flags) {
   ::ShellExecuteW(NULL, L"open", kHelpCenterUrl, NULL, NULL, SW_SHOW);
 }