Add user action for changing the active window in Ash overview mode

ash/wm/overview/window_selector.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.h"
 
 #include <algorithm>
 #include <functional>
 #include <set>
 #include <vector>
 
 #include "ash/accessibility_delegate.h"
 #include "ash/ash_switches.h"
 #include "ash/metrics/user_metrics_recorder.h"
 #include "ash/root_window_controller.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/switchable_windows.h"
+#include "ash/wm/mru_window_tracker.h"
 #include "ash/wm/overview/window_grid.h"
 #include "ash/wm/overview/window_selector_delegate.h"
 #include "ash/wm/overview/window_selector_item.h"
 #include "ash/wm/panels/panel_layout_manager.h"
 #include "ash/wm/window_state.h"
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
 #include "third_party/skia/include/core/SkPaint.h"
 #include "third_party/skia/include/core/SkPath.h"
@@ skipping 357 matching lines @@
   ScopedVector<WindowGrid>::iterator iter =
       std::find(grid_list_.begin(), grid_list_.end(), grid);
   DCHECK(iter != grid_list_.end());
   grid_list_.erase(iter);
   // TODO(flackr): Use the previous index for more than two displays.
   selected_grid_index_ = 0;
   if (grid_list_.empty())
     CancelSelection();
 }
 
+void WindowSelector::SelectWindow(aura::Window* window) {
+  // Record UMA_WINDOW_OVERVIEW_ACTIVE_WINDOW_CHANGED if the user is selecting
+  // a window other than the window that was active prior to entering overview
+  // mode (i.e., the window at the front of the MRU list).
+  MruWindowTracker::WindowList window_list =
+      Shell::GetInstance()->mru_window_tracker()->BuildMruWindowList();
+  if (window_list.size() > 0 && window_list[0] != window) {
+    Shell::GetInstance()->metrics()->RecordUserMetricsAction(
+        UMA_WINDOW_OVERVIEW_ACTIVE_WINDOW_CHANGED);
+  }
+
+  wm::GetWindowState(window)->Activate();
+}
+
 bool WindowSelector::HandleKeyEvent(views::Textfield* sender,
                                     const ui::KeyEvent& key_event) {
   if (key_event.type() != ui::ET_KEY_PRESSED)
     return false;
 
   switch (key_event.key_code()) {
     case ui::VKEY_ESCAPE:
       CancelSelection();
       break;
     case ui::VKEY_UP:
@@ skipping 17 matching lines @@
       // Ignore if no item is selected.
       if (!grid_list_[selected_grid_index_]->is_selecting())
         return false;
       UMA_HISTOGRAM_COUNTS_100("Ash.WindowSelector.ArrowKeyPresses",
                                num_key_presses_);
       UMA_HISTOGRAM_CUSTOM_COUNTS(
           "Ash.WindowSelector.KeyPressesOverItemsRatio",
           (num_key_presses_ * 100) / num_items_, 1, 300, 30);
       Shell::GetInstance()->metrics()->RecordUserMetricsAction(
           UMA_WINDOW_OVERVIEW_ENTER_KEY);
-      wm::GetWindowState(grid_list_[selected_grid_index_]->
-                         SelectedWindow()->GetWindow())->Activate();
+      SelectWindow(
+          grid_list_[selected_grid_index_]->SelectedWindow()->GetWindow());
       break;
     default:
       // Not a key we are interested in, allow the textfield to handle it.
       return false;
   }
   return true;
 }
 
 void WindowSelector::OnDisplayAdded(const gfx::Display& display) {
 }
@@ skipping 129 matching lines @@
   for (size_t i = 0;
       i <= grid_list_.size() &&
       grid_list_[selected_grid_index_]->Move(direction, animate); i++) {
     // TODO(flackr): If there are more than two monitors, move between grids
     // in the requested direction.
     selected_grid_index_ = (selected_grid_index_ + 1) % grid_list_.size();
   }
 }
 
 }  // namespace ash