Re-write many calls to WrapUnique() with MakeUnique()

chrome/browser/page_load_metrics/metrics_web_contents_observer_unittest.cc

 // Copyright (c) 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 "chrome/browser/page_load_metrics/metrics_web_contents_observer.h"
 
 #include <memory>
 #include <vector>
 
 #include "base/macros.h"
@@ skipping 62 matching lines @@
 
   bool IsPrerendering(content::WebContents* web_contents) override {
     return is_prerendering_;
   }
   bool IsNewTabPageUrl(const GURL& url) override { return is_ntp_; }
   void set_is_prerendering(bool is_prerendering) {
     is_prerendering_ = is_prerendering;
   }
   void set_is_ntp(bool is_ntp) { is_ntp_ = is_ntp; }
   void RegisterObservers(PageLoadTracker* tracker) override {
-    tracker->AddObserver(base::WrapUnique(new TestPageLoadMetricsObserver(
-        &updated_timings_, &complete_timings_, &observed_committed_urls_)));
+    tracker->AddObserver(base::MakeUnique<TestPageLoadMetricsObserver>(
+        &updated_timings_, &complete_timings_, &observed_committed_urls_));
   }
   const std::vector<PageLoadTiming>& updated_timings() const {
     return updated_timings_;
   }
   const std::vector<PageLoadTiming>& complete_timings() const {
     return complete_timings_;
   }
 
   // currently_committed_urls passed to OnStart().
   const std::vector<GURL>& observed_committed_urls_from_on_start() const {
@@ skipping 407 matching lines @@
 
   histogram_tester_.ExpectTotalCount(
       internal::kPageLoadCompletedAfterAppBackground, 2);
   histogram_tester_.ExpectBucketCount(
       internal::kPageLoadCompletedAfterAppBackground, false, 1);
   histogram_tester_.ExpectBucketCount(
       internal::kPageLoadCompletedAfterAppBackground, true, 1);
 }
 
 }  // namespace page_load_metrics