Added Ash.SystemMenu.DefaultView.VisibleItems histogram.

ash/common/system/tray/system_tray_bubble.cc

Index: ash/common/system/tray/system_tray_bubble.cc
diff --git a/ash/common/system/tray/system_tray_bubble.cc b/ash/common/system/tray/system_tray_bubble.cc
index ebe94148f4bb0c0cc063faeb53604107ba141025..c131853fe7435fd44909ba6c20b9cad7291352ba 100644
--- a/ash/common/system/tray/system_tray_bubble.cc
+++ b/ash/common/system/tray/system_tray_bubble.cc
@@ -4,6 +4,9 @@
 
 #include "ash/common/system/tray/system_tray_bubble.h"
 
+#include <utility>
+#include <vector>
+
 #include "ash/common/system/tray/system_tray.h"
 #include "ash/common/system/tray/system_tray_delegate.h"
 #include "ash/common/system/tray/system_tray_item.h"
@@ -11,6 +14,7 @@
 #include "ash/common/system/tray/tray_constants.h"
 #include "ash/common/system/tray/tray_popup_item_container.h"
 #include "ash/common/wm_shell.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "ui/compositor/layer.h"
 #include "ui/compositor/layer_animation_observer.h"
@@ -274,8 +278,24 @@ bool SystemTrayBubble::ShouldShowShelf() const {
   return false;
 }
 
+void SystemTrayBubble::RecordVisibleRowMetrics() {
+  if (bubble_type_ != BUBBLE_TYPE_DEFAULT) {
+    DCHECK(false) << "Only the BUBBLE_TYPE_DEFAULT BubbleType is supported.";

[tdanderson, 2016/07/19 21:58:40]

Not sure if we need a DCHECK or a message here.

[bruthig, 2016/07/20 18:15:52]

Removed.

+    return;
+  }
+
+  for (const std::pair<SystemTrayItem::ItemType, views::View*>& pair :
+       tray_item_view_map_) {
+    if (pair.second->visible()) {
+      UMA_HISTOGRAM_ENUMERATION("Ash.SystemMenu.DefaultView.VisibleItems",
+                                pair.first, SystemTrayItem::COUNT);
+    }
+  }
+}
+
 void SystemTrayBubble::CreateItemViews(LoginStatus login_status) {
-  std::vector<views::View*> item_views;
+  tray_item_view_map_.clear();
+
   // If a system modal dialog is present, create the same tray as
   // in locked state.
   if (WmShell::Get()->IsSystemModalWindowOpen() &&
@@ -284,33 +304,44 @@ void SystemTrayBubble::CreateItemViews(LoginStatus login_status) {
   }
 
   views::View* focus_view = NULL;
+  const bool is_default_bubble = bubble_type_ == BUBBLE_TYPE_DEFAULT;
   for (size_t i = 0; i < items_.size(); ++i) {
-    views::View* view = NULL;
+    views::View* item_view = NULL;

[tdanderson, 2016/07/19 21:58:40]

nit: nullptr here and line 306

[bruthig, 2016/07/20 18:15:52]

Done.

     switch (bubble_type_) {
       case BUBBLE_TYPE_DEFAULT:
-        view = items_[i]->CreateDefaultView(login_status);
+        item_view = items_[i]->CreateDefaultView(login_status);
         if (items_[i]->restore_focus())
-          focus_view = view;
+          focus_view = item_view;
         break;
       case BUBBLE_TYPE_DETAILED:
-        view = items_[i]->CreateDetailedView(login_status);
+        item_view = items_[i]->CreateDetailedView(login_status);
         break;
       case BUBBLE_TYPE_NOTIFICATION:
-        view = items_[i]->CreateNotificationView(login_status);
+        item_view = items_[i]->CreateNotificationView(login_status);
         break;
     }
-    if (view)
-      item_views.push_back(view);
+    if (item_view) {
+      views::View* tray_popup_item_container = new TrayPopupItemContainer(
+          item_view, is_default_bubble, is_default_bubble);
+

[tdanderson, 2016/07/19 21:58:39]

nit: omit blank lines at 326 and 328

[bruthig, 2016/07/20 18:15:52]

Done.

+      bubble_view_->AddChildView(tray_popup_item_container);
+
+      tray_item_view_map_[items_[i]->type()] = tray_popup_item_container;
+    }
   }
 
-  bool is_default_bubble = bubble_type_ == BUBBLE_TYPE_DEFAULT;
-  for (size_t i = 0; i < item_views.size(); ++i) {
-    // For default view, draw bottom border for each item, except the last
-    // 2 items, which are the bottom header row and the one just above it.
-    bubble_view_->AddChildView(new TrayPopupItemContainer(
-        item_views[i], is_default_bubble,
-        is_default_bubble && (i < item_views.size() - 2)));
+  // For default view, draw bottom border for each item, except the last
+  // 2 items, which are the bottom header row and the one just above it.
+  const int view_count = bubble_view_->child_count();
+  if (is_default_bubble && view_count > 1) {
+    bubble_view_->child_at(view_count - 1)
+        ->SetBorder(views::Border::NullBorder());
+    if (view_count > 2) {
+      bubble_view_->child_at(view_count - 2)
+          ->SetBorder(views::Border::NullBorder());
+    }
   }
+
   if (focus_view)
     focus_view->RequestFocus();
 }