Add new UMA stats to get a handle on Downloads UI Usage

chrome/browser/ui/views/download/download_shelf_view.cc

Index: chrome/browser/ui/views/download/download_shelf_view.cc
diff --git a/chrome/browser/ui/views/download/download_shelf_view.cc b/chrome/browser/ui/views/download/download_shelf_view.cc
index f60424a4e1b14b7c3968ceeffb6c5f5a96cf0c69..70b82af7e48794b93c2c21c0937fb47e4d277bb5 100644
--- a/chrome/browser/ui/views/download/download_shelf_view.cc
+++ b/chrome/browser/ui/views/download/download_shelf_view.cc
@@ -15,6 +15,7 @@
 #include "chrome/browser/ui/views/download/download_item_view.h"
 #include "chrome/browser/ui/views/frame/browser_view.h"
 #include "content/browser/download/download_item.h"
+#include "content/browser/download/download_stats.h"
 #include "content/browser/download/download_manager.h"
 #include "content/browser/tab_contents/navigation_entry.h"
 #include "grit/generated_resources.h"
@@ -87,6 +88,7 @@ int CenterPosition(int size, int target_size) {
 DownloadShelfView::DownloadShelfView(Browser* browser, BrowserView* parent)
     : browser_(browser),
       parent_(parent),
+      auto_closed_(false),
       ALLOW_THIS_IN_INITIALIZER_LIST(
           mouse_watcher_(this, this, gfx::Insets())) {
   mouse_watcher_.set_notify_on_exit_time_ms(kNotifyOnExitTimeMS);
@@ -152,6 +154,7 @@ void DownloadShelfView::AddDownload(BaseDownloadItemModel* download_model) {
 }
 
 void DownloadShelfView::MouseMovedOutOfView() {
+  auto_closed_ = true;

[Randy Smith (Not in Mondays), 2011/10/04 18:34:31]

This seems weird to me.  Are you sure?  Two concerns:
+ I thought that the Windows shelf closed on last unopened download open; this
function doesn't sound like it's used in that case.
+ If a shelf can close and reopen, that doesn't reset auto_closed_ to false.

[benjhayden, 2011/10/06 21:25:16]

Done.

   Close();
 }
 
@@ -383,6 +386,13 @@ void DownloadShelfView::Show() {
 }
 
 void DownloadShelfView::Close() {
+  int num_pending = 0;
+  for (size_t i = 0; i < download_views_.size(); ++i) {
+    if (download_views_[i]->download()->IsInProgress())
+      ++num_pending;
+  }
+  download_stats::RecordShelfClose(
+      download_views_.size(), num_pending, auto_closed_);
   parent_->SetDownloadShelfVisible(false);
   shelf_animation_->Hide();
 }