Add window overview mode behind --ash-enable-overview-mode flag to F5 key.

ash/wm/window_selector_controller.cc

+// Copyright (c) 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/window_selector_controller.h"
+
+#include "ash/session_state_delegate.h"
+#include "ash/shell.h"
+#include "ash/wm/window_cycle_controller.h"
+#include "ash/wm/window_selector.h"
+#include "ash/wm/window_util.h"
+
+namespace ash {
+
+WindowSelectorController::WindowSelectorController() {
+}
+
+WindowSelectorController::~WindowSelectorController() {
+}
+
+// static
+bool WindowSelectorController::CanSelect() {
+  // Don't allow a window overview if the screen is locked or a modal dialog is
+  // open.
+  return !Shell::GetInstance()->session_state_delegate()->IsScreenLocked() &&
+         !Shell::GetInstance()->IsSystemModalWindowOpen();
+}
+
+void WindowSelectorController::ToggleOverview() {
+  if (window_selector_.get()) {
+    window_selector_.reset();
+  } else {
+    std::vector<aura::Window*> windows =
+        WindowCycleController::BuildWindowList(NULL, false);

[flackr, 2013/07/29 15:38:37]

This will change to the window tracker MRU list when
https://codereview.chromium.org/20708005/ lands.

+    // Don't enter overview mode with no windows.
+    if (windows.empty())
+      return;
+
+    // Deactivating the window will hide popup windows like the omnibar or
+    // open menus.
+    aura::Window* active_window = wm::GetActiveWindow();
+    if (active_window)
+      wm::DeactivateWindow(active_window);
+    window_selector_.reset(new WindowSelector(windows, this));
+  }
+}
+
+void WindowSelectorController::SelectWindow(aura::Window* window) {
+  window_selector_.reset();
+  wm::ActivateWindow(window);

[sky, 2013/07/30 16:39:19]

Does this do the right thing if window was minimized?

[flackr, 2013/07/31 20:06:12]

Added call to Show to set correct state (consistent with WindowCycleList::Step
used for alt-tab). Also, there were issues with handling events on "minimized"
windows so I've temporarily restored windows, remembering that they were
minimized.

+  // TODO(flackr): Ensure window gets added to MRU windows used for
+  // BuildWindowList.
+}
+
+}  // namespace ash