ChromeShellDelegate: Cleanup: move initial focus code to ash

This change makes mru_window_tracker.cc a SessionObserver and
moves the initial focus logic there.

Bug: 665064
Change-Id: I5c125e0bbe62b9d2c8d809d519d3ccfeade76f8f
Reviewed-on: https://chromium-review.googlesource.com/1070854
Commit-Queue: Steven Bennetts <stevenjb@chromium.org>
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#561886}

ash/wm/mru_window_tracker.cc

@@ -8,6 +8,7 @@
 
 #include "ash/public/cpp/shell_window_ids.h"
 #include "ash/public/cpp/window_properties.h"
+#include "ash/session/session_controller.h"
 #include "ash/shell.h"
 #include "ash/wm/focus_rules.h"
 #include "ash/wm/switchable_windows.h"
@@ -102,11 +103,13 @@ MruWindowTracker::WindowList BuildWindowListInternal(
 //////////////////////////////////////////////////////////////////////////////
 // MruWindowTracker, public:
 
-MruWindowTracker::MruWindowTracker() : ignore_window_activations_(false) {
+MruWindowTracker::MruWindowTracker() {
   Shell::Get()->activation_client()->AddObserver(this);
+  Shell::Get()->session_controller()->AddObserver(this);
 }
 
 MruWindowTracker::~MruWindowTracker() {
+  Shell::Get()->session_controller()->RemoveObserver(this);
   Shell::Get()->activation_client()->RemoveObserver(this);
   for (auto* window : mru_windows_)
     window->RemoveObserver(this);
@@ -156,6 +159,20 @@ void MruWindowTracker::SetIgnoreActivations(bool ignore) {
     SetActiveWindow(wm::GetActiveWindow());
 }
 
+// SessionObserver
+
+// Restore focus after the user session has started. This is needed because some
+// windows can be opened in the background while the login UI is still active
+// since we currently restore browser windows before login UI is deleted.
+void MruWindowTracker::OnUserSessionAdded(const AccountId& account_id) {
+  if (user_session_focus_restored_)
+    return;
+  user_session_focus_restored_ = true;
+  aura::Window::Windows mru_list = BuildMruWindowList();
+  if (!mru_list.empty())
+    mru_list.front()->Focus();
+}
+
 //////////////////////////////////////////////////////////////////////////////
 // MruWindowTracker, private:
 

ash/wm/mru_window_tracker.h

@@ -9,6 +9,7 @@
 #include <vector>
 
 #include "ash/ash_export.h"
+#include "ash/session/session_observer.h"
 #include "base/macros.h"
 #include "ui/aura/window_observer.h"
 #include "ui/wm/public/activation_change_observer.h"
@@ -18,7 +19,8 @@ namespace ash {
 // Maintains a most recently used list of windows. This is used for window
 // cycling using Alt+Tab and overview mode.
 class ASH_EXPORT MruWindowTracker : public ::wm::ActivationChangeObserver,
-                                    public aura::WindowObserver {
+                                    public aura::WindowObserver,
+                                    public SessionObserver {
  public:
   using WindowList = std::vector<aura::Window*>;
 
@@ -45,6 +47,9 @@ class ASH_EXPORT MruWindowTracker : public ::wm::ActivationChangeObserver,
   // windows to the front of the MRU window list.
   void SetIgnoreActivations(bool ignore);
 
+  // SessionObserver
+  void OnUserSessionAdded(const AccountId& account_id) override;
+
  private:
   // Updates the mru_windows_ list to insert/move |active_window| at/to the
   // front.
@@ -62,7 +67,8 @@ class ASH_EXPORT MruWindowTracker : public ::wm::ActivationChangeObserver,
   // through, sorted by most recently used.
   std::list<aura::Window*> mru_windows_;
 
-  bool ignore_window_activations_;
+  bool ignore_window_activations_ = false;
+  bool user_session_focus_restored_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(MruWindowTracker);
 };

chrome/browser/ui/ash/DEPS

@@ -60,7 +60,11 @@ specific_include_rules = {
   ],
   # https://crbug.com/665064
   "chrome_shell_delegate.*": [
-    "+ash",
+    # https://crbug.com/756054
+    "+ash/accessibility/accessibility_delegate.h",
+    # https://crbug.com/557397
+    "+ash/screenshot_delegate.h",
+    "+ash/shell_delegate.h",
   ],
   # https://crbug.com/672277
   "session_util\.cc": [

chrome/browser/ui/ash/chrome_shell_delegate.cc

@@ -11,8 +11,7 @@
 
 #include "ash/accessibility/accessibility_delegate.h"
 #include "ash/public/cpp/accessibility_types.h"
-#include "ash/shell.h"
-#include "ash/wm/mru_window_tracker.h"
+#include "ash/screenshot_delegate.h"
 #include "base/command_line.h"
 #include "base/macros.h"
 #include "build/build_config.h"
@@ -69,16 +68,6 @@ namespace {
 const char kKeyboardShortcutHelpPageUrl[] =
     "https://support.google.com/chromebook/answer/183101";
 
-void InitAfterFirstSessionStart() {
-  // Restore focus after the user session is started.  It's needed because some
-  // windows can be opened in background while login UI is still active because
-  // we currently restore browser windows before login UI is deleted.
-  aura::Window::Windows mru_list =
-      ash::Shell::Get()->mru_window_tracker()->BuildMruWindowList();
-  if (!mru_list.empty())
-    mru_list.front()->Focus();
-}
-
 class AccessibilityDelegateImpl : public ash::AccessibilityDelegate {
  public:
   AccessibilityDelegateImpl() = default;
@@ -247,12 +236,6 @@ void ChromeShellDelegate::Observe(int type,
       }
       break;
     }
-    case chrome::NOTIFICATION_SESSION_STARTED:
-      // InitAfterFirstSessionStart() should only be called once upon system
-      // start.
-      if (user_manager::UserManager::Get()->GetLoggedInUsers().size() < 2)
-        InitAfterFirstSessionStart();
-      break;
     default:
       NOTREACHED() << "Unexpected notification " << type;
   }
@@ -261,6 +244,4 @@ void ChromeShellDelegate::Observe(int type,
 void ChromeShellDelegate::PlatformInit() {
   registrar_.Add(this, chrome::NOTIFICATION_LOGIN_USER_PROFILE_PREPARED,
                  content::NotificationService::AllSources());
-  registrar_.Add(this, chrome::NOTIFICATION_SESSION_STARTED,
-                 content::NotificationService::AllSources());
 }