Fix incorrect window show state after session restore.

chrome/browser/sessions/session_restore.cc

Index: chrome/browser/sessions/session_restore.cc
diff --git a/chrome/browser/sessions/session_restore.cc b/chrome/browser/sessions/session_restore.cc
index aca211c8d7bfe979dff23c9fc44f7a8ff4296d36..3f464e59877ffed85d94f4933519a8baa2371ebb 100644
--- a/chrome/browser/sessions/session_restore.cc
+++ b/chrome/browser/sessions/session_restore.cc
@@ -382,11 +382,15 @@ class SessionRestoreImpl : public content::NotificationObserver {
     // windows has the same id as specified in active_window_id.
     Browser* browser_to_activate = nullptr;
 
-    // Determine if there is a visible window.
+    // Determine if there is a visible window, or if the active window exists.
+    // Even if all windows are ui::SHOW_STATE_MINIMIZED, if one of them is the
+    // active window it will be made visible by the call to
+    // browser_to_activate->window()->Activate() later on in this method.
     bool has_visible_browser = false;
     for (std::vector<sessions::SessionWindow*>::iterator i = windows->begin();
          i != windows->end(); ++i) {
-      if ((*i)->show_state != ui::SHOW_STATE_MINIMIZED)
+      if ((*i)->show_state != ui::SHOW_STATE_MINIMIZED ||
+          (*i)->window_id.id() == active_window_id)

[sky, 2015/09/28 14:54:05]

How is that the active window is in a minimized state?

[shrike, 2015/09/28 17:53:41]

As browser windows become active, SessionService::OnBrowserSetLastActive() gets
called from BrowserList::SetLastActive(). However if you minimize the last
visible browser window, SessionService::OnBrowserSetLastActive() does not get
called, so session restore is stuck remembering the last active browser window.

To clear out the last active browser window
SessionService::OnBrowserSetLastActive() would have to be called with either a
dummy browser window object or a nullptr. It looks like a nullptr can't be
passed in because SessionService::OnBrowserSet() immediately calls
SessionService::ShouldTrackBrowser() and it looks like that method would crash
if it received a nullptr.

[sky, 2015/09/28 19:04:01]

Ok, makes sense.

         has_visible_browser = true;
     }