Minimized windows should not be activated by another user in multiprofile scenario.

chrome/browser/ui/ash/session_state_delegate_chromeos.cc

Index: chrome/browser/ui/ash/session_state_delegate_chromeos.cc
diff --git a/chrome/browser/ui/ash/session_state_delegate_chromeos.cc b/chrome/browser/ui/ash/session_state_delegate_chromeos.cc
index 9b1edd275b5fe1d6da7d3ddc9f3727a3eb772e2f..5fb741930f7e7e58c56488e3a39a3ce4f51513e2 100644
--- a/chrome/browser/ui/ash/session_state_delegate_chromeos.cc
+++ b/chrome/browser/ui/ash/session_state_delegate_chromeos.cc
@@ -66,8 +66,14 @@ SessionStateDelegateChromeos::GetBrowserContextForWindow(
       chrome::MultiUserWindowManager::GetInstance()->GetWindowOwner(window);
   const user_manager::User* user =
       user_manager::UserManager::Get()->FindUser(user_id);
-  DCHECK(user);
-  return chromeos::ProfileHelper::Get()->GetProfileByUserUnsafe(user);

[oshima, 2015/04/07 19:53:44]

why this change?

[xdai1, 2015/04/09 17:22:40]

In Login screen, we might fail this check since there is no active user at that
moment.

[oshima, 2015/04/09 17:50:48]

Why this wasn't an issue before? Do you think this is because of
crbug.com/475318?

[xdai1, 2015/04/09 22:45:25]

Because in this fix we will call this GetBrowserContextForWindow() function in
AshFocusRules::IsWindowConsideredVisibleForActivation() function, which will be
used to check if the window can be activatable even in the login screen. But
without this fix, we don't need to worry about this since we always call
GetBrowserContextForWindow() after we have an active user.

It has nothing to do with crbug.com/475318. 

[oshima, 2015/04/10 20:39:48]

what kind of "user_id" would you get if it's in login screen?

+  return user ? (chromeos::ProfileHelper::Get()->GetProfileByUserUnsafe(user))
+              : NULL;
+}
+
+const std::string& SessionStateDelegateChromeos::GetUserPresentingWindow(
+    aura::Window* window) {
+  return chrome::MultiUserWindowManager::GetInstance()->GetUserPresentingWindow(
+      window);
 }
 
 int SessionStateDelegateChromeos::GetMaximumNumberOfLoggedInUsers() const {