Add UMA histograms for WebUSB.

chrome/browser/chrome_webusb_browser_client.cc

 // Copyright 2015 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 "chrome/browser/chrome_webusb_browser_client.h"
 
 #include <utility>
 
 #include "base/macros.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/net/referrer.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/host_desktop.h"
 #include "chrome/browser/ui/scoped_tabbed_browser_displayer.h"
 #include "chrome/grit/generated_resources.h"
 #include "chrome/grit/theme_resources.h"
 #include "content/public/common/origin_util.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/page_transition_types.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/window_open_disposition.h"
 #include "ui/gfx/image/image.h"
 #include "ui/message_center/message_center.h"
 #include "ui/message_center/notification.h"
 #include "ui/message_center/notification_delegate.h"
 #include "url/gurl.h"
 
 namespace {
 
 const char kWebUsbDetectorNotificationID[] = "webusb.detector";
 
+// Reasons the notification may be closed. These are used in histograms so do
+// not remove/reorder entries. Only add at the end just before
+// WEBUSB_NOTIFICATION_CLOSED_MAX. Also remember to update the enum listing in
+// tools/metrics/histograms/histograms.xml.
+enum WebUsbNotificationClosed {
+  // The notification was dismissed but not by the user (either automatically
+  // or because the device was unplugged).
+  WEBUSB_NOTIFICATION_CLOSED,
+  // The user closed the notification.
+  WEBUSB_NOTIFICATION_CLOSED_BY_USER,
+  // The user clicked on the notification.
+  WEBUSB_NOTIFICATION_CLOSED_CLICKED,
+  // Maximum value for the enum.
+  WEBUSB_NOTIFICATION_CLOSED_MAX
+};
+
+void RecordNotificationClosure(WebUsbNotificationClosed disposition) {
+  UMA_HISTOGRAM_ENUMERATION("WebUsb.NotificationClosed", disposition,
+                            WEBUSB_NOTIFICATION_CLOSED_MAX);
+}
+
 Browser* GetBrowser() {
   chrome::ScopedTabbedBrowserDisplayer browser_displayer(
       ProfileManager::GetActiveUserProfile(), chrome::GetActiveDesktop());
   DCHECK(browser_displayer.browser());
   return browser_displayer.browser();
 }
 
 void OpenURL(const GURL& url) {
   GetBrowser()->OpenURL(
       content::OpenURLParams(url, content::Referrer(), NEW_FOREGROUND_TAB,
                              ui::PAGE_TRANSITION_AUTO_TOPLEVEL, true));
 }
 
 // Delegate for webusb notification
 class WebUsbNotificationDelegate : public message_center::NotificationDelegate {
  public:
   WebUsbNotificationDelegate(const GURL& landing_page,
                              const std::string& notification_id)
       : landing_page_(landing_page), notification_id_(notification_id) {}
 
   void Click() override {
+    clicked_ = true;
     OpenURL(landing_page_);
     message_center::MessageCenter::Get()->RemoveNotification(
         notification_id_, false /* by_user */);
   }
 
+  void Close(bool by_user) override {
+    if (clicked_)
+      RecordNotificationClosure(WEBUSB_NOTIFICATION_CLOSED_CLICKED);
+    else if (by_user)
+      RecordNotificationClosure(WEBUSB_NOTIFICATION_CLOSED_BY_USER);
+    else
+      RecordNotificationClosure(WEBUSB_NOTIFICATION_CLOSED);
+  }
+
  private:
   ~WebUsbNotificationDelegate() override = default;
 
   GURL landing_page_;
   std::string notification_id_;
+  bool clicked_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(WebUsbNotificationDelegate);
 };
 
 }  // namespace
 
 ChromeWebUsbBrowserClient::ChromeWebUsbBrowserClient() {}
 
 ChromeWebUsbBrowserClient::~ChromeWebUsbBrowserClient() {}
 
@@ skipping 29 matching lines @@
 }
 
 void ChromeWebUsbBrowserClient::OnDeviceRemoved(
     const std::string& notification_id) {
   message_center::MessageCenter* message_center =
       message_center::MessageCenter::Get();
   if (message_center->FindVisibleNotificationById(notification_id)) {
     message_center->RemoveNotification(notification_id, false /* by_user */);
   }
 }