Split UserMetrics into API vs. implementation. Move API to content/public.

content/browser/user_metrics.cc

-// Copyright (c) 2011 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 "content/browser/user_metrics.h"
-
-#include "base/bind.h"
-#include "content/public/browser/browser_thread.h"
-#include "content/public/browser/notification_service.h"
-#include "content/public/browser/notification_types.h"
-
-using content::BrowserThread;
-
-void UserMetrics::RecordAction(const UserMetricsAction& action) {
-  Record(action.str_);
-}
-
-void UserMetrics::RecordComputedAction(const std::string& action) {
-  Record(action.c_str());
-}
-
-void UserMetrics::Record(const char *action) {
-  if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
-    BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
-                            base::Bind(&UserMetrics::CallRecordOnUI, action));
-    return;
-  }
-
-  content::NotificationService::current()->Notify(
-      content::NOTIFICATION_USER_ACTION,
-      content::NotificationService::AllSources(),
-      content::Details<const char*>(&action));
-}
-
-void UserMetrics::CallRecordOnUI(const std::string& action) {
-  Record(action.c_str());
-}