Add a new metric for how many times permissions prompts are shown.

chrome/browser/permissions/permission_bubble_request_impl.cc

 // Copyright 2014 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/permissions/permission_bubble_request_impl.h"
 
 #include "build/build_config.h"
 #include "chrome/browser/permissions/permission_context_base.h"
 #include "chrome/browser/permissions/permission_uma_util.h"
 #include "chrome/grit/generated_resources.h"
@@ skipping 143 matching lines @@
 
 void PermissionBubbleRequestImpl::Cancelled() {
   RegisterActionTaken();
   permission_decided_callback_.Run(false, CONTENT_SETTING_DEFAULT);
 }
 
 void PermissionBubbleRequestImpl::RequestFinished() {
   is_finished_ = true;
   delete_callback_.Run();
 }
+
+PermissionBubbleType PermissionBubbleRequestImpl::GetPermissionBubbleType()
+    const {
+  return PermissionBubbleType::PERMISSION;
+}