Add start/finish navigation to startup metrics.

chrome/browser/metrics/first_web_contents_profiler.h

Index: chrome/browser/metrics/first_web_contents_profiler.h
diff --git a/chrome/browser/metrics/first_web_contents_profiler.h b/chrome/browser/metrics/first_web_contents_profiler.h
index 832d55539165642601e13c74422136012096a31a..9402f492608d48c1c1d40981f9d4421bafec1512 100644
--- a/chrome/browser/metrics/first_web_contents_profiler.h
+++ b/chrome/browser/metrics/first_web_contents_profiler.h
@@ -5,6 +5,8 @@
 #ifndef CHROME_BROWSER_METRICS_FIRST_WEB_CONTENTS_PROFILER_H_
 #define CHROME_BROWSER_METRICS_FIRST_WEB_CONTENTS_PROFILER_H_
 
+#include <set>
+
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/histogram.h"
 #include "content/public/browser/web_contents_observer.h"
@@ -42,17 +44,23 @@ class FirstWebContentsProfiler : public content::WebContentsObserver {
   };
 
   explicit FirstWebContentsProfiler(content::WebContents* web_contents);
-  ~FirstWebContentsProfiler() = default;
+  ~FirstWebContentsProfiler();
 
   // content::WebContentsObserver:
   void DidFirstVisuallyNonEmptyPaint() override;
   void DocumentOnLoadCompletedInMainFrame() override;
+  void DidStartNavigation(
+      content::NavigationHandle* navigation_handle) override;
+  void DidFinishNavigation(
+      content::NavigationHandle* navigation_handle) override;
   void NavigationEntryCommitted(
       const content::LoadCommittedDetails& load_details) override;
   void WasHidden() override;
   void WebContentsDestroyed() override;
 
-  // Whether this instance has finished collecting all of its metrics.
+  // Whether this instance has finished collecting first-paint and main-frame-
+  // load metrics (navigation metrics are recorded on a best effort but don't
+  // prevent the FirstWebContentsProfiler from calling it).
   bool IsFinishedCollectingMetrics();
 
   // Logs |finish_reason| to UMA and deletes this FirstWebContentsProfiler.
@@ -72,6 +80,20 @@ class FirstWebContentsProfiler : public content::WebContentsObserver {
   // Whether an attempt was made to collect the "MainFrameLoad" metric.
   bool collected_load_metric_;
 
+  // Whether an attempt was made to collect the "MainNavigationStart" metric.
+  bool collected_main_navigation_start_metric_;
+
+  // Whether an attempt was made to collect the "MainNavigationFinished" metric.
+  bool collected_main_navigation_finished_metric_;
+
+  // Whether an attempt was made to collect the "MainNavigationFinishedAll"
+  // metric.
+  bool collected_main_navigation_finished_all_metric_;
+
+  // The set of all live NavigationHandles for the main frame (i.e. handles seen
+  // by DidStartNavigation() but not by DidFinishNavigation()).
+  std::set<content::NavigationHandle*> main_navigation_handles_;
+
   // Histogram that keeps track of response times for the watched thread.
   base::HistogramBase* responsiveness_histogram_;