Avoid loading the last used browser profile in app_controller_mac when it's not needed.

chrome/browser/app_controller_mac.mm

 // 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.
 
 #import "chrome/browser/app_controller_mac.h"
 
 #include "apps/app_shim/app_shim_mac.h"
 #include "apps/app_shim/extension_app_shim_handler_mac.h"
 #include "apps/shell_window_registry.h"
 #include "base/auto_reset.h"
@@ skipping 543 matching lines @@
     // window remain. It seems that the new key window for the app is not set
     // until after this notification is fired, so a check is performed after the
     // run loop is allowed to spin.
     [self performSelector:@selector(checkForAnyKeyWindows)
                withObject:nil
                afterDelay:0.0];
   }
 
   // If the window changed to a new BrowserWindowController, update the profile.
   id windowController = [[notify object] windowController];
-  if ([notify name] == NSWindowDidBecomeMainNotification &&
-      [windowController isKindOfClass:[BrowserWindowController class]]) {
+  if (![windowController isKindOfClass:[BrowserWindowController class]])
+    return;
+
+  if ([notify name] == NSWindowDidBecomeMainNotification) {
     // If the profile is incognito, use the original profile.
     Profile* newProfile = [windowController profile]->GetOriginalProfile();
     [self windowChangedToProfile:newProfile];
   } else if (chrome::GetTotalBrowserCount() == 0) {
     [self windowChangedToProfile:
         g_browser_process->profile_manager()->GetLastUsedProfile()];
   }
 }
 
 - (void)activeSpaceDidChange:(NSNotification*)notify {
@@ skipping 675 matching lines @@
   // handles requests from services.
   NSArray* types = [NSArray arrayWithObjects:NSStringPboardType, nil];
   [app registerServicesMenuSendTypes:types returnTypes:types];
 }
 
 - (Profile*)lastProfile {
   // Return the profile of the last-used BrowserWindowController, if available.
   if (lastProfile_)
     return lastProfile_;
 
-  // On first launch, no profile will be stored, so use last from Local State.
-  if (g_browser_process->profile_manager())
-    return g_browser_process->profile_manager()->GetLastUsedProfile();
+  // On first launch, use the logic that ChromeBrowserMain uses to determine
+  // the initial profile.
+  ProfileManager* profile_manager = g_browser_process->profile_manager();
+  if (!profile_manager)
+    return NULL;
 
-  return NULL;
+  return profile_manager->GetProfile(GetStartupProfilePath(
+      profile_manager->user_data_dir(),
+      *CommandLine::ForCurrentProcess()));
 }
 
 // Various methods to open URLs that we get in a native fashion. We use
 // StartupBrowserCreator here because on the other platforms, URLs to open come
 // through the ProcessSingleton, and it calls StartupBrowserCreator. It's best
 // to bottleneck the openings through that for uniform handling.
 
 - (void)openUrls:(const std::vector<GURL>&)urls {
   // If the browser hasn't started yet, just queue up the URLs.
   if (!startupComplete_) {
@@ skipping 207 matching lines @@
 
 //---------------------------------------------------------------------------
 
 namespace app_controller_mac {
 
 bool IsOpeningNewWindow() {
   return g_is_opening_new_window;
 }
 
 }  // namespace app_controller_mac