Allow Alt-Tab to move the focus to docked windows.

ash/wm/overview/window_selector_controller.cc

 // Copyright 2013 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.
 
 #include "ash/wm/overview/window_selector_controller.h"
 
 #include <vector>
 
 #include "ash/metrics/user_metrics_recorder.h"
 #include "ash/root_window_controller.h"
@@ skipping 28 matching lines @@
 }
 
 void WindowSelectorController::ToggleOverview() {
   if (IsSelecting()) {
     OnSelectionEnded();
   } else {
     // Don't start overview if window selection is not allowed.
     if (!CanSelect())
       return;
 
-    std::vector<aura::Window*> windows = ash::Shell::GetInstance()->
-        mru_window_tracker()->BuildMruWindowList();
+    aura::Window::Windows windows =
+        ash::Shell::GetInstance()->mru_window_tracker()->BuildMruWindowList();
+
+    for (aura::Window::Windows::iterator iter = windows.begin();

[flackr, 2015/04/07 15:08:39]

Use std::remove_if for linear runtime?

[oshima, 2015/04/07 18:00:32]

This is linear too. To use remove_if, I need to change IsSelectable to
IsNotSelectable, or define functor. Please let me know if you prefer remove_if,
and I'll update the code.

[flackr, 2015/04/07 18:10:33]

aura::Window::Windows looks to be a vector making each erase(iter) operation
linear time so for lots of docked windows this would become quadratic wouldn't
it?

[oshima, 2015/04/07 20:35:29]

You're absolutely right, sorry. Updated.

+         iter != windows.end();) {
+      if (WindowSelector::IsSelectable(*iter))
+        ++iter;
+      else
+        iter = windows.erase(iter);
+    }
+
     // Don't enter overview mode with no windows.
     if (windows.empty())
       return;
 
     Shell::GetInstance()->OnOverviewModeStarting();
     window_selector_.reset(new WindowSelector(this));
     window_selector_->Init(windows);
     OnSelectionStarted();
   }
 }
@@ skipping 18 matching lines @@
 
 void WindowSelectorController::OnSelectionStarted() {
   if (!last_selection_time_.is_null()) {
     UMA_HISTOGRAM_LONG_TIMES(
         "Ash.WindowSelector.TimeBetweenUse",
         base::Time::Now() - last_selection_time_);
   }
 }
 
 }  // namespace ash