[Cleanup] Move all browsertests to use ScopedFeatureList to modify features

chrome/browser/page_load_metrics/observers/ads_page_load_metrics_observer.cc

 // Copyright 2017 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/observers/ads_page_load_metrics_observer.h"
 
 #include <string>
 #include <utility>
 
 #include "base/feature_list.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/strings/string_util.h"
 #include "chrome/browser/page_load_metrics/page_load_metrics_util.h"
+#include "chrome/common/chrome_features.h"
 #include "content/public/browser/navigation_handle.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/web_contents.h"
 #include "url/gurl.h"
 
 namespace {
 
-const base::Feature kAdsFeature{"AdsMetrics", base::FEATURE_ENABLED_BY_DEFAULT};
-
 bool FrameIsAd(content::NavigationHandle* navigation_handle) {
   // Because sub-resource filtering isn't always enabled, and doesn't work
   // well in monitoring mode (no CSS enforcement), it's difficult to identify
   // ads. Google ads are prevalent and easy to track, so we'll start by
   // tracking those. Note that the frame name can be very large, so be careful
   // to avoid full string searches if possible.
   // TODO(jkarlin): Track other ad networks that are easy to identify.
 
   // In case the navigation aborted, look up the RFH by the Frame Tree Node
   // ID. It returns the committed frame host or the initial frame host for the
@@ skipping 30 matching lines @@
 
 AdsPageLoadMetricsObserver::AdFrameData::AdFrameData(
     FrameTreeNodeId frame_tree_node_id)
     : frame_bytes(0u),
       frame_bytes_uncached(0u),
       frame_tree_node_id(frame_tree_node_id) {}
 
 // static
 std::unique_ptr<AdsPageLoadMetricsObserver>
 AdsPageLoadMetricsObserver::CreateIfNeeded() {
-  if (!base::FeatureList::IsEnabled(kAdsFeature))
+  if (!base::FeatureList::IsEnabled(features::kAdsFeature))
     return nullptr;
   return base::MakeUnique<AdsPageLoadMetricsObserver>();
 }
 
 AdsPageLoadMetricsObserver::AdsPageLoadMetricsObserver() = default;
 AdsPageLoadMetricsObserver::~AdsPageLoadMetricsObserver() = default;
 
 page_load_metrics::PageLoadMetricsObserver::ObservePolicy
 AdsPageLoadMetricsObserver::OnCommit(
     content::NavigationHandle* navigation_handle,
@@ skipping 210 matching lines @@
 void AdsPageLoadMetricsObserver::ProcessOngoingNavigationResource(
     FrameTreeNodeId frame_tree_node_id) {
   const auto& frame_id_and_request =
       ongoing_navigation_resources_.find(frame_tree_node_id);
   if (frame_id_and_request == ongoing_navigation_resources_.end())
     return;
 
   ProcessLoadedResource(frame_id_and_request->second);
   ongoing_navigation_resources_.erase(frame_id_and_request);
 }