Add PageLoad.* metrics for Offline Previews

chrome/browser/page_load_metrics/page_load_metrics_initialize.cc

Index: chrome/browser/page_load_metrics/page_load_metrics_initialize.cc
diff --git a/chrome/browser/page_load_metrics/page_load_metrics_initialize.cc b/chrome/browser/page_load_metrics/page_load_metrics_initialize.cc
index 78c00758d54037e89f90577ce8d61fafbdf3bbe2..fd460c8f57a7bf16f9cccd038dae8cc0fc78d2cd 100644
--- a/chrome/browser/page_load_metrics/page_load_metrics_initialize.cc
+++ b/chrome/browser/page_load_metrics/page_load_metrics_initialize.cc
@@ -10,20 +10,21 @@
 #if defined(OS_ANDROID)
 #include "chrome/browser/page_load_metrics/observers/android_page_load_metrics_observer.h"
 #endif  // OS_ANDROID
 #include "chrome/browser/page_load_metrics/observers/aborts_page_load_metrics_observer.h"
 #include "chrome/browser/page_load_metrics/observers/core_page_load_metrics_observer.h"
 #include "chrome/browser/page_load_metrics/observers/data_reduction_proxy_metrics_observer.h"
 #include "chrome/browser/page_load_metrics/observers/document_write_page_load_metrics_observer.h"
 #include "chrome/browser/page_load_metrics/observers/from_gws_page_load_metrics_observer.h"
 #include "chrome/browser/page_load_metrics/observers/google_captcha_observer.h"
 #include "chrome/browser/page_load_metrics/observers/https_engagement_metrics/https_engagement_page_load_metrics_observer.h"
+#include "chrome/browser/page_load_metrics/observers/previews_page_load_metrics_observer.h"
 #include "chrome/browser/page_load_metrics/observers/service_worker_page_load_metrics_observer.h"
 #include "chrome/browser/page_load_metrics/observers/stale_while_revalidate_metrics_observer.h"
 #include "chrome/browser/prerender/prerender_contents.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/search/search.h"
 #include "components/rappor/rappor_service.h"
 #include "content/public/browser/web_contents.h"
 #include "url/gurl.h"
 
 namespace chrome {
@@ -62,20 +63,22 @@ void PageLoadMetricsEmbedder::RegisterObservers(
       new data_reduction_proxy::DataReductionProxyMetricsObserver()));
   tracker->AddObserver(base::WrapUnique(new FromGWSPageLoadMetricsObserver()));
   tracker->AddObserver(
       base::WrapUnique(new google_captcha_observer::GoogleCaptchaObserver()));
   // TODO(ricea): Remove this in April 2016 or before. crbug.com/348877
   tracker->AddObserver(
       base::WrapUnique(new chrome::StaleWhileRevalidateMetricsObserver()));
   tracker->AddObserver(
       base::WrapUnique(new DocumentWritePageLoadMetricsObserver()));
   tracker->AddObserver(
+      base::WrapUnique(new previews::PreviewsPageLoadMetricsObserver()));
+  tracker->AddObserver(
       base::WrapUnique(new ServiceWorkerPageLoadMetricsObserver()));
   tracker->AddObserver(
       base::WrapUnique(new HttpsEngagementPageLoadMetricsObserver(
           web_contents_->GetBrowserContext())));
 #if defined(OS_ANDROID)
   tracker->AddObserver(
       base::WrapUnique(new AndroidPageLoadMetricsObserver(web_contents_)));
 #endif  // OS_ANDROID
 }