Hide the main window when Set-As-Default dialog is present.

chrome/browser/ui/startup/startup_browser_creator_impl.cc

Index: chrome/browser/ui/startup/startup_browser_creator_impl.cc
diff --git a/chrome/browser/ui/startup/startup_browser_creator_impl.cc b/chrome/browser/ui/startup/startup_browser_creator_impl.cc
index adcb2f366181de34fb85c5084bf6f867a1759888..e304a682999191831a9afba2a775d4a3bbb5f067 100644
--- a/chrome/browser/ui/startup/startup_browser_creator_impl.cc
+++ b/chrome/browser/ui/startup/startup_browser_creator_impl.cc
@@ -781,10 +781,16 @@ Browser* StartupBrowserCreatorImpl::OpenTabsInBrowser(Browser* browser,
       chrome::ActivateTabAt(browser, 0, false);
   }
 
-  browser->window()->Show();
-  // TODO(jcampan): http://crbug.com/8123 we should not need to set the initial
-  //                focus explicitly.
-  chrome::GetActiveWebContents(browser)->GetView()->SetInitialFocus();
+  // The default behaviour is to show the window, as expressed by the default
+  // value of StartupBrowserCreated::show_main_browser_window_. If this was set
+  // to true ahead of this place, it means another task must have been spawned
+  // to take care of that.
+  if (!browser_creator_ || browser_creator_->show_main_browser_window()) {
+    browser->window()->Show();
+    // TODO(jcampan): http://crbug.com/8123 we should not need to set the
+    //                initial focus explicitly.
+    chrome::GetActiveWebContents(browser)->GetView()->SetInitialFocus();
+  }
 
   return browser;
 }