Fix FirstWebContentsProfiler not getting created when using session restore.

This regressed in r420175 because a different code path is taken that doesn't go through browser_navigator.cc's CreateTargetContents.

BUG=650349

Review-Url: https://codereview.chromium.org/2388803003
Cr-Commit-Position: refs/heads/master@{#422883}

chrome/browser/metrics/first_web_contents_profiler.cc

@@ -19,6 +19,16 @@
 #include "components/startup_metric_utils/browser/startup_metric_utils.h"
 #include "content/public/browser/navigation_handle.h"
 
+void FirstWebContentsProfiler::WebContentsStarted(
+    content::WebContents* web_contents) {
+  static bool first_web_contents_profiled = false;
+  if (first_web_contents_profiled)
+    return;
+
+  first_web_contents_profiled = true;
+  new FirstWebContentsProfiler(web_contents);
+}
+
 FirstWebContentsProfiler::FirstWebContentsProfiler(
     content::WebContents* web_contents)
     : content::WebContentsObserver(web_contents),

chrome/browser/metrics/first_web_contents_profiler.h

@@ -20,7 +20,10 @@ class WebContents;
 // class.
 class FirstWebContentsProfiler : public content::WebContentsObserver {
  public:
-  explicit FirstWebContentsProfiler(content::WebContents* web_contents);
+  // Creates a profiler for the active web contents. If there are multiple
+  // browsers, the first one is chosen. The resulting FirstWebContentsProfiler
+  // owns itself.
+  static void WebContentsStarted(content::WebContents* web_contents);
 
  private:
   // Reasons for which profiling is deemed complete. Logged in UMA (do not re-
@@ -40,7 +43,7 @@ class FirstWebContentsProfiler : public content::WebContentsObserver {
     ABANDON_NAVIGATION_ERROR = 5,
     ENUM_MAX
   };
-
+  explicit FirstWebContentsProfiler(content::WebContents* web_contents);
   ~FirstWebContentsProfiler() override = default;
 
   // content::WebContentsObserver:

chrome/browser/sessions/session_restore.cc

@@ -31,6 +31,7 @@
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/lifetime/keep_alive_types.h"
 #include "chrome/browser/lifetime/scoped_keep_alive.h"
+#include "chrome/browser/metrics/first_web_contents_profiler.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/search/search.h"
 #include "chrome/browser/sessions/session_restore_delegate.h"
@@ -548,6 +549,7 @@ class SessionRestoreImpl : public content::NotificationObserver {
         if (!is_selected_tab)
           continue;
 
+        FirstWebContentsProfiler::WebContentsStarted(contents);
         ShowBrowser(browser, browser->tab_strip_model()->GetIndexOfWebContents(
                                  contents));
         // TODO(sky): remove. For debugging 368236.

chrome/browser/ui/browser_navigator.cc

@@ -377,11 +377,7 @@ content::WebContents* CreateTargetContents(const chrome::NavigateParams& params,
 #endif
 
 #if !defined(OS_ANDROID)
-  static bool first_web_contents_profiled = false;
-  if (!first_web_contents_profiled) {
-    first_web_contents_profiled = true;
-    new FirstWebContentsProfiler(target_contents);
-  }
+  FirstWebContentsProfiler::WebContentsStarted(target_contents);
 #endif  // !defined(OS_ANDROID)
   return target_contents;
 }