Add .SingleTab and .MultiTabs suffix to Startup.FirstWebContents.MainNavigationStart histogram.

chrome/browser/metrics/first_web_contents_profiler.cc

Index: chrome/browser/metrics/first_web_contents_profiler.cc
diff --git a/chrome/browser/metrics/first_web_contents_profiler.cc b/chrome/browser/metrics/first_web_contents_profiler.cc
index dcff83a5e2d9247a5307b811832ce65a239e8d4a..9a219ced2ce21c8612e5f30b96999d8bb1711673 100644
--- a/chrome/browser/metrics/first_web_contents_profiler.cc
+++ b/chrome/browser/metrics/first_web_contents_profiler.cc
@@ -2,14 +2,13 @@
 // 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/macros.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/time/time.h"
 #include "build/build_config.h"
@@ -20,29 +19,82 @@
 #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"
+#include "content/public/browser/web_contents.h"
+#include "content/public/browser/web_contents_observer.h"
 #include "content/public/common/browser_side_navigation_policy.h"
 
-// static
-void FirstWebContentsProfiler::Start() {
-  for (auto* browser : *BrowserList::GetInstance()) {
-    content::WebContents* web_contents =
-        browser->tab_strip_model()->GetActiveWebContents();
-    if (web_contents) {
-      // FirstWebContentsProfiler owns itself and is also bound to
-      // |web_contents|'s lifetime by observing WebContentsDestroyed().
-      new FirstWebContentsProfiler(web_contents);
-      return;
-    }
-  }
-}
+namespace {
+
+class FirstWebContentsProfiler : public content::WebContentsObserver {
+ public:
+  FirstWebContentsProfiler(content::WebContents* web_contents,
+                           startup_metric_utils::WebContentsWorkload workload);
+
+ private:
+  // Reasons for which profiling is deemed complete. Logged in UMA (do not re-
+  // order or re-assign).
+  enum FinishReason {
+    // All metrics were successfully gathered.
+    DONE = 0,
+    // Abandon if blocking UI was shown during startup.
+    ABANDON_BLOCKING_UI = 1,
+    // Abandon if the content is hidden (lowers scheduling priority).
+    ABANDON_CONTENT_HIDDEN = 2,
+    // Abandon if the content is destroyed.
+    ABANDON_CONTENT_DESTROYED = 3,
+    // Abandon if the WebContents navigates away from its initial page.
+    ABANDON_NEW_NAVIGATION = 4,
+    // Abandon if the WebContents fails to load (e.g. network error, etc.).
+    ABANDON_NAVIGATION_ERROR = 5,
+    ENUM_MAX
+  };
+
+  ~FirstWebContentsProfiler() override = default;
+
+  // content::WebContentsObserver:
+  void DidFirstVisuallyNonEmptyPaint() override;
+  void DocumentOnLoadCompletedInMainFrame() override;
+  void DidStartNavigation(
+      content::NavigationHandle* navigation_handle) override;
+  void DidFinishNavigation(
+      content::NavigationHandle* navigation_handle) override;
+  void WasHidden() override;
+  void WebContentsDestroyed() override;
+
+  // 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.
+  void FinishedCollectingMetrics(FinishReason finish_reason);
+
+  // Whether an attempt was made to collect the "NonEmptyPaint" metric.
+  bool collected_paint_metric_;
+
+  // 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_;
+
+  const startup_metric_utils::WebContentsWorkload workload_;
+
+  DISALLOW_COPY_AND_ASSIGN(FirstWebContentsProfiler);
+};
 
 FirstWebContentsProfiler::FirstWebContentsProfiler(
-    content::WebContents* web_contents)
+    content::WebContents* web_contents,
+    startup_metric_utils::WebContentsWorkload workload)
     : content::WebContentsObserver(web_contents),
       collected_paint_metric_(false),
       collected_load_metric_(false),
       collected_main_navigation_start_metric_(false),
-      collected_main_navigation_finished_metric_(false) {}
+      collected_main_navigation_finished_metric_(false),
+      workload_(workload) {}
 
 void FirstWebContentsProfiler::DidFirstVisuallyNonEmptyPaint() {
   if (collected_paint_metric_)
@@ -100,7 +152,7 @@ void FirstWebContentsProfiler::DidStartNavigation(
 
   collected_main_navigation_start_metric_ = true;
   startup_metric_utils::RecordFirstWebContentsMainNavigationStart(
-      base::TimeTicks::Now());
+      base::TimeTicks::Now(), workload_);
 }
 
 void FirstWebContentsProfiler::DidFinishNavigation(
@@ -136,7 +188,7 @@ void FirstWebContentsProfiler::DidFinishNavigation(
 
   if (content::IsBrowserSideNavigationEnabled()) {
     startup_metric_utils::RecordFirstWebContentsMainNavigationStart(
-        navigation_handle->NavigationStart());
+        navigation_handle->NavigationStart(), workload_);
     collected_main_navigation_start_metric_ = true;
   }
 
@@ -175,4 +227,32 @@ void FirstWebContentsProfiler::FinishedCollectingMetrics(
   delete this;
 }
 
-#endif  // !defined(OS_ANDROID)
+}  // namespace
+
+namespace metrics {
+
+void BeginFirstWebContentsProfiling() {
+  using startup_metric_utils::WebContentsWorkload;
+
+  const BrowserList* browser_list = BrowserList::GetInstance();
+
+  const auto first_browser = browser_list->begin();
+  if (first_browser == browser_list->end())
+    return;
+
+  const TabStripModel* tab_strip = (*first_browser)->tab_strip_model();
+  DCHECK(!tab_strip->empty());
+
+  content::WebContents* web_contents = tab_strip->GetActiveWebContents();
+  DCHECK(web_contents);
+
+  const bool single_tab = browser_list->size() == 1 && tab_strip->count() == 1;
+
+  // FirstWebContentsProfiler owns itself and is also bound to
+  // |web_contents|'s lifetime by observing WebContentsDestroyed().
+  new FirstWebContentsProfiler(web_contents,
+                               single_tab ? WebContentsWorkload::SINGLE_TAB
+                                          : WebContentsWorkload::MULTI_TABS);
+}
+
+}  // namespace metrics