Use TimeTicks as much as possible in startup_metric_utils.

mandoline/ui/desktop_ui/browser_manager.cc

 // 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.
 
 #include "mandoline/ui/desktop_ui/browser_manager.h"
 
 #include "base/command_line.h"
 #include "components/mus/public/cpp/window.h"
 #include "components/mus/public/cpp/window_observer.h"
 #include "mandoline/ui/desktop_ui/browser_window.h"
 
 namespace mandoline {
 
 namespace {
 
 const char kGoogleURL[] = "http://www.google.com";
 
 }  // namespace
 
 BrowserManager::BrowserManager()
-    : app_(nullptr), startup_time_(base::Time::Now()) {}
+    : app_(nullptr), startup_ticks_(base::TimeTicks::Now()) {}
 
 BrowserManager::~BrowserManager() {
   while (!browsers_.empty())
     (*browsers_.begin())->Close();
   DCHECK(browsers_.empty());
 }
 
 BrowserWindow* BrowserManager::CreateBrowser(const GURL& default_url) {
   BrowserWindow* browser = new BrowserWindow(app_, host_factory_.get(), this);
   browsers_.insert(browser);
@@ skipping 40 matching lines @@
   connection->AddService<LaunchHandler>(this);
   return true;
 }
 
 void BrowserManager::Create(mojo::ApplicationConnection* connection,
                             mojo::InterfaceRequest<LaunchHandler> request) {
   launch_handler_bindings_.AddBinding(this, request.Pass());
 }
 
 }  // namespace mandoline