Add Incognito main frame navigations per session metric for non-iOS.

For better measurement of Incognito usage,
"Profile.Incognito.MainFrameNavigationsPerSession" metric is added to
record the activity length of Incognito sessions.

This metric will be added for iOS in a different CL.

Bug: 966747
Change-Id: I4d163f0ec603916949972d9dc290e4247a1125e1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2421821
Commit-Queue: Ramin Halavati <rhalavati@chromium.org>
Reviewed-by: Mihai Sardarescu <msarda@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Reviewed-by: Ramin Halavati <rhalavati@chromium.org>
Cr-Commit-Position: refs/heads/master@{#812105}

chrome/browser/profiles/off_the_record_profile_impl.cc

@@ -215,12 +215,16 @@ OffTheRecordProfileImpl::~OffTheRecordProfileImpl() {
   // other profile-related destroy notifications are dispatched.
   ShutdownStoragePartitions();
 
-  // Store incognito lifetime histogram.
-  if (!IsGuestSession()) {
+  // Store incognito lifetime and navigations count histogram.
+  if (IsIncognitoProfile()) {
     auto duration = base::Time::Now() - start_time_;
     base::UmaHistogramCustomCounts(
         "Profile.Incognito.Lifetime", duration.InMinutes(), 1,
         base::TimeDelta::FromDays(28).InMinutes(), 100);
+
+    base::UmaHistogramCounts1000(
+        "Profile.Incognito.MainFrameNavigationsPerSession",
+        main_frame_navigations_);
   }
 }
 
@@ -654,3 +658,7 @@ void OffTheRecordProfileImpl::UpdateDefaultZoomLevel() {
       ->OnDefaultZoomLevelChanged();
 }
 #endif  // !defined(OS_ANDROID)
+
+void OffTheRecordProfileImpl::RecordMainFrameNavigation() {
+  main_frame_navigations_++;
+}

chrome/browser/profiles/off_the_record_profile_impl.h

@@ -127,6 +127,7 @@ class OffTheRecordProfileImpl : public Profile {
   content::SharedCorsOriginAccessList* GetSharedCorsOriginAccessList() override;
   content::NativeFileSystemPermissionContext*
   GetNativeFileSystemPermissionContext() override;
+  void RecordMainFrameNavigation() override;
 
  private:
 #if !defined(OS_ANDROID)
@@ -163,6 +164,9 @@ class OffTheRecordProfileImpl : public Profile {
   std::unique_ptr<ProfileKey> key_;
 
   base::FilePath last_selected_directory_;
+
+  // Number of main frame navigations done by this profile.
+  unsigned int main_frame_navigations_ = 0;
 };
 
 #endif  // CHROME_BROWSER_PROFILES_OFF_THE_RECORD_PROFILE_IMPL_H_

chrome/browser/profiles/profile.h

@@ -500,6 +500,8 @@ class Profile : public content::BrowserContext {
 
   virtual void SetCreationTimeForTesting(base::Time creation_time) = 0;
 
+  virtual void RecordMainFrameNavigation() = 0;
+
  protected:
   void set_is_guest_profile(bool is_guest_profile) {
     is_guest_profile_ = is_guest_profile;

chrome/browser/profiles/profile_impl.h

@@ -173,6 +173,7 @@ class ProfileImpl : public Profile {
 #endif  // defined(OS_CHROMEOS)
 
   void SetCreationTimeForTesting(base::Time creation_time) override;
+  void RecordMainFrameNavigation() override {}
 
  private:
 #if defined(OS_CHROMEOS)

chrome/browser/tab_contents/navigation_metrics_recorder.cc

@@ -86,6 +86,7 @@ void NavigationMetricsRecorder::DidFinishNavigation(
   navigation_metrics::RecordMainFrameNavigation(
       url, navigation_handle->IsSameDocument(), profile->IsOffTheRecord(),
       ProfileMetrics::GetBrowserProfileType(profile));
+  profile->RecordMainFrameNavigation();
 
   if (url.SchemeIsHTTPOrHTTPS() && !navigation_handle->IsSameDocument() &&
       !navigation_handle->IsDownload() && !profile->IsOffTheRecord()) {

chrome/test/base/testing_profile.h

@@ -367,6 +367,8 @@ class TestingProfile : public Profile {
 
   PrefService* GetOffTheRecordPrefs() override;
 
+  void RecordMainFrameNavigation() override {}
+
   void set_profile_name(const std::string& profile_name) {
     profile_name_ = profile_name;
   }