Add UMA for studying download cancellation reasons

chrome/browser/android/download/chrome_download_manager_overwrite_infobar_delegate.cc

Index: chrome/browser/android/download/chrome_download_manager_overwrite_infobar_delegate.cc
diff --git a/chrome/browser/android/download/chrome_download_manager_overwrite_infobar_delegate.cc b/chrome/browser/android/download/chrome_download_manager_overwrite_infobar_delegate.cc
index f4cf6a25e9cac60624fd144e22bb68a6cf041cc4..71d6bdedd3647ac577b8745ae40c251e321935ad 100644
--- a/chrome/browser/android/download/chrome_download_manager_overwrite_infobar_delegate.cc
+++ b/chrome/browser/android/download/chrome_download_manager_overwrite_infobar_delegate.cc
@@ -14,9 +14,12 @@
 #include "chrome/browser/infobars/infobar_service.h"
 #include "chrome/browser/ui/android/infobars/download_overwrite_infobar.h"
 #include "components/infobars/core/infobar.h"
+#include "content/public/browser/android/download_controller_android.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/web_contents.h"
 
+using content::DownloadControllerAndroid;
+
 namespace {
 
 void DeleteExistingDownloadFile(
@@ -96,6 +99,8 @@ std::string ChromeDownloadManagerOverwriteInfoBarDelegate::GetDirFullPath()
 
 void ChromeDownloadManagerOverwriteInfoBarDelegate::InfoBarDismissed() {
   file_selected_callback_.Run(base::FilePath());
+  DownloadControllerAndroid::RecordDownloadCancelReason(
+      DownloadControllerAndroid::CANCEL_REASON_OVERWRITE_INFOBAR_DISMISSED);
 }
 
 void ChromeDownloadManagerOverwriteInfoBarDelegate::CreateNewFileInternal(