Metrics logging for user engagement of the Reload and Feedback buttons

ios/chrome/browser/ui/sad_tab/sad_tab_view.mm

 // 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.
 
 #import "ios/chrome/browser/ui/sad_tab/sad_tab_view.h"
 
+#include "base/metrics/histogram_macros.h"
 #include "base/strings/sys_string_conversions.h"
 #include "components/grit/components_scaled_resources.h"
 #include "components/strings/grit/components_strings.h"
+#include "components/ui_metrics/sadtab_metrics_types.h"
 #include "ios/chrome/browser/chrome_url_constants.h"
 #import "ios/chrome/browser/ui/colors/MDCPalette+CrAdditions.h"
 #import "ios/chrome/browser/ui/commands/UIKit+ChromeExecuteCommand.h"
 #import "ios/chrome/browser/ui/commands/ios_command_ids.h"
 #import "ios/chrome/browser/ui/commands/open_url_command.h"
 #include "ios/chrome/browser/ui/rtl_geometry.h"
 #import "ios/chrome/browser/ui/uikit_ui_util.h"
 #import "ios/chrome/browser/ui/url_loader.h"
 #import "ios/chrome/browser/ui/util/label_link_controller.h"
 #import "ios/third_party/material_components_ios/src/components/Buttons/src/MaterialButtons.h"
@@ skipping 529 matching lines @@
   self.containerView.frame = AlignRectOriginAndSizeToPixels(
       CGRectMake(containerOriginX, containerOriginY, containerSize.width,
                  containerSize.height));
 }
 
 #pragma mark Util
 
 - (void)handleActionButtonTapped:(id)sender {
   switch (self.mode) {
     case SadTabViewMode::RELOAD:
+      UMA_HISTOGRAM_ENUMERATION(ui_metrics::kSadTabReloadHistogramKey,
+                                ui_metrics::SadTabEvent::BUTTON_CLICKED,
+                                ui_metrics::SadTabEvent::MAX_SAD_TAB_EVENT);
       self.navigationManager->Reload(web::ReloadType::NORMAL, true);
       break;
     case SadTabViewMode::FEEDBACK: {
+      UMA_HISTOGRAM_ENUMERATION(ui_metrics::kSadTabFeedbackHistogramKey,
+                                ui_metrics::SadTabEvent::BUTTON_CLICKED,
+                                ui_metrics::SadTabEvent::MAX_SAD_TAB_EVENT);
       GenericChromeCommand* command =
           [[GenericChromeCommand alloc] initWithTag:IDC_REPORT_AN_ISSUE];
       [self chromeExecuteCommand:command];
       break;
     }
   };
 }
 
 + (UIColor*)sadTabBackgroundColor {
   return [UIColor colorWithWhite:kBackgroundColorBrightness alpha:1.0];
 }
 
 @end