Refactor ownership model for FirstWebContentsProfiler.

chrome/browser/metrics/first_web_contents_profiler.cc

 // Copyright 2014 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.
 
 #if !defined(OS_ANDROID)
 
 #include "chrome/browser/metrics/first_web_contents_profiler.h"
 
 #include <string>
 
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/time/time.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_iterator.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "components/metrics/profiler/tracking_synchronizer.h"
 #include "components/metrics/proto/profiler_event.pb.h"
 #include "components/startup_metric_utils/browser/startup_metric_utils.h"
 #include "content/public/browser/navigation_handle.h"
 
-scoped_ptr<FirstWebContentsProfiler>
-FirstWebContentsProfiler::CreateProfilerForFirstWebContents(
-    Delegate* delegate) {
-  DCHECK(delegate);
-  for (chrome::BrowserIterator iterator; !iterator.done(); iterator.Next()) {
-    Browser* browser = *iterator;
+// static
+void FirstWebContentsProfiler::Start() {
+  for (chrome::BrowserIterator browser_it; !browser_it.done();
+       browser_it.Next()) {
     content::WebContents* web_contents =
-        browser->tab_strip_model()->GetActiveWebContents();
+        browser_it->tab_strip_model()->GetActiveWebContents();
     if (web_contents) {
-      return scoped_ptr<FirstWebContentsProfiler>(
-          new FirstWebContentsProfiler(web_contents, delegate));
+      // FirstWebContentsProfiler owns itself and is also bound to
+      // |web_contents|'s lifetime by observing WebContentsDestroyed().
+      new FirstWebContentsProfiler(web_contents);
+      return;
     }
   }
-  return nullptr;
 }
 
 FirstWebContentsProfiler::FirstWebContentsProfiler(
-    content::WebContents* web_contents,
-    Delegate* delegate)
+    content::WebContents* web_contents)
     : content::WebContentsObserver(web_contents),
       collected_paint_metric_(false),
       collected_load_metric_(false),
       collected_main_navigation_start_metric_(false),
       collected_main_navigation_finished_metric_(false),
-      finished_(false),
-      delegate_(delegate) {}
+      finished_(false) {}
 
 void FirstWebContentsProfiler::DidFirstVisuallyNonEmptyPaint() {
   if (collected_paint_metric_)
     return;
   if (startup_metric_utils::WasNonBrowserUIDisplayed()) {
     FinishedCollectingMetrics(FinishReason::ABANDON_BLOCKING_UI);
     return;
   }
 
   collected_paint_metric_ = true;
@@ skipping 111 matching lines @@
     }
     finished_ = true;
   }
 
   // Continue recording deprecated v1 stats (see |finished_|) except in
   // scenarios where stats collection was already being abandonned previously.
   // TODO(gab): Delete right away when getting rid of |finished_|.
   if (IsFinishedCollectingMetrics() ||
       finish_reason == FinishReason::ABANDON_CONTENT_DESTROYED ||
       finish_reason == FinishReason::ABANDON_BLOCKING_UI) {
-    delegate_->ProfilerFinishedCollectingMetrics();
+    delete this;
   }
 }
 
 #endif  // !defined(OS_ANDROID)