[Extensions] Add metrics for reporting abuse in the uninstall dialog

BUG=484869

Review URL: https://codereview.chromium.org/1119903004

Cr-Commit-Position: refs/heads/master@{#328792}
diff --git a/chrome/browser/extensions/extension_uninstall_dialog.cc b/chrome/browser/extensions/extension_uninstall_dialog.cc
index 3642804..0b06ceb 100644
--- a/chrome/browser/extensions/extension_uninstall_dialog.cc
+++ b/chrome/browser/extensions/extension_uninstall_dialog.cc
@@ -8,6 +8,7 @@
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/field_trial.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/extensions/extension_util.h"
 #include "chrome/browser/profiles/profile.h"
@@ -135,6 +136,16 @@
           "ShowCheckbox";
 }
 
+void ExtensionUninstallDialog::OnDialogClosed(CloseAction action) {
+  // We don't want to artificially weight any of the options, so only record if
+  // reporting abuse was available.
+  if (ShouldShowReportAbuseCheckbox()) {
+    UMA_HISTOGRAM_ENUMERATION("Extensions.UninstallDialogAction",
+                              action,
+                              CLOSE_ACTION_LAST);
+  }
+}
+
 void ExtensionUninstallDialog::HandleReportAbuse() {
   chrome::NavigateParams params(
       profile_,