customtabs: Send time to first contentful paint to the caller.

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 50927ff95721e8baa539bbdb14865d667846756d..34579079ab8e27cef9244289565c52bf89b35b62 100644
--- a/chrome/browser/page_load_metrics/page_load_metrics_initialize.cc
+++ b/chrome/browser/page_load_metrics/page_load_metrics_initialize.cc
@@ -6,6 +6,9 @@
 
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
+#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"
@@ -36,7 +39,8 @@ class PageLoadMetricsEmbedder
   // page_load_metrics::PageLoadMetricsEmbedderInterface:
   bool IsPrerendering(content::WebContents* web_contents) override;
   bool IsNewTabPageUrl(const GURL& url) override;
-  void RegisterObservers(page_load_metrics::PageLoadTracker* tracker) override;
+  void RegisterObservers(page_load_metrics::PageLoadTracker* tracker,
+                         content::WebContents* web_contents) override;
 
  private:
   content::WebContents* const web_contents_;
@@ -51,7 +55,8 @@ PageLoadMetricsEmbedder::PageLoadMetricsEmbedder(
 PageLoadMetricsEmbedder::~PageLoadMetricsEmbedder() {}
 
 void PageLoadMetricsEmbedder::RegisterObservers(
-    page_load_metrics::PageLoadTracker* tracker) {
+    page_load_metrics::PageLoadTracker* tracker,
+    content::WebContents* web_contents) {
   // These classes are owned by the metrics.
   tracker->AddObserver(base::WrapUnique(new AbortsPageLoadMetricsObserver()));
   tracker->AddObserver(base::WrapUnique(new CorePageLoadMetricsObserver()));
@@ -69,6 +74,10 @@ void PageLoadMetricsEmbedder::RegisterObservers(
       base::WrapUnique(new ServiceWorkerPageLoadMetricsObserver()));
   tracker->AddObserver(
       base::WrapUnique(new HttpsEngagementPageLoadMetricsObserver()));
+#if defined(OS_ANDROID)
+  tracker->AddObserver(
+      base::WrapUnique(new AndroidPageLoadMetricsObserver(web_contents)));
+#endif  // OS_ANDROID
 }
 
 bool PageLoadMetricsEmbedder::IsPrerendering(