Add Guest availability metric for signin Intercept.

"Signin.Intercept.Guest.Availability" metric is added to record if Guest
option is available at signin intercept or not and why.

Bug: 1157764
Change-Id: I00dc3bb07b6b6cec758c206b1046a0c2e767d7b1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2620621Reviewed-by: David Roger <droger@chromium.org>
Reviewed-by: Weilun Shi <sweilun@chromium.org>
Reviewed-by: Ilya Sherman <isherman@chromium.org>
Commit-Queue: Ramin Halavati <rhalavati@chromium.org>
Cr-Commit-Position: refs/heads/master@{#842910}

chrome/browser/signin/dice_web_signin_interceptor.cc

@@ -88,11 +88,35 @@ bool HasNoBrowser(content::WebContents* web_contents) {
   return chrome::FindBrowserWithWebContents(web_contents) == nullptr;
 }
 
-bool GuestOptionAvailable() {
-  return Profile::IsEphemeralGuestProfileEnabled() &&
-         !ProfileManager::GuestProfileExists() &&
-         g_browser_process->local_state()->GetBoolean(
-             prefs::kBrowserGuestModeEnabled);
+// Different conditions which make Guest option available or not.
+// These values are persisted to logs. Entries should not be renumbered and
+// numeric values should never be reused.
+enum class SigninInterceptGuestAvailability {
+  kAvailable = 0,
+  kGuestAlreadyOpen = 1,
+  kGuestBlocked = 2,
+  kEphemeralGuestDisabled = 3,
+  kMaxValue = kEphemeralGuestDisabled
+};
+
+SigninInterceptGuestAvailability GetGuestOptionAvailablity() {
+  if (!Profile::IsEphemeralGuestProfileEnabled())
+    return SigninInterceptGuestAvailability::kEphemeralGuestDisabled;
+
+  if (ProfileManager::GuestProfileExists())
+    return SigninInterceptGuestAvailability::kGuestAlreadyOpen;
+
+  if (!g_browser_process->local_state()->GetBoolean(
+          prefs::kBrowserGuestModeEnabled)) {
+    return SigninInterceptGuestAvailability::kGuestBlocked;
+  }
+  return SigninInterceptGuestAvailability::kAvailable;
+}
+
+void RecordGuestOptionAvailablity(
+    SigninInterceptGuestAvailability availability) {
+  base::UmaHistogramEnumeration("Signin.Intercept.Guest.Availability",
+                                availability);
 }
 
 }  // namespace
@@ -407,10 +431,12 @@ void DiceWebSigninInterceptor::OnExtendedAccountInfoUpdated(
       ->GetProfileAttributesStorage()
       .GetProfileAttributesWithPath(profile_->GetPath(), &entry);
   SkColor profile_color = GenerateNewProfileColor(entry).color;
+  auto guest_option_availability = GetGuestOptionAvailablity();
   Delegate::BubbleParameters bubble_parameters{
       *interception_type, info, GetPrimaryAccountInfo(identity_manager_),
       GetAutogeneratedThemeColors(profile_color).frame_color,
-      GuestOptionAvailable()};
+      guest_option_availability ==
+          SigninInterceptGuestAvailability::kAvailable};
   interception_bubble_handle_ = delegate_->ShowSigninInterceptionBubble(
       web_contents(), bubble_parameters,
       base::BindOnce(&DiceWebSigninInterceptor::OnProfileCreationChoice,
@@ -420,6 +446,7 @@ void DiceWebSigninInterceptor::OnExtendedAccountInfoUpdated(
       *interception_type == SigninInterceptionType::kEnterprise
           ? SigninInterceptionHeuristicOutcome::kInterceptEnterprise
           : SigninInterceptionHeuristicOutcome::kInterceptMultiUser);
+  RecordGuestOptionAvailablity(guest_option_availability);
 }
 
 void DiceWebSigninInterceptor::OnExtendedAccountInfoFetchTimeout() {

tools/metrics/histograms/enums.xml

@@ -68700,6 +68700,13 @@ https://www.dmtf.org/sites/default/files/standards/documents/DSP0134_2.7.1.pdf
   <int value="10" label="Undo">The sync was aborted with an undo button.</int>
 </enum>
 
+<enum name="SigninInterceptGuestAvailability">
+  <int value="0" label="Guest option available"/>
+  <int value="1" label="Guest already open"/>
+  <int value="2" label="Guest mode blocked by policy"/>
+  <int value="3" label="Ephemeral Guest profile disabled"/>
+</enum>
+
 <enum name="SigninInterceptHeuristicOutcome">
   <int value="0" label="Intercept: profile switch"/>
   <int value="1" label="Intercept: multi-user"/>

tools/metrics/histograms/histograms_xml/signin/histograms.xml

@@ -407,6 +407,16 @@ prefs when the profile is loaded.  -->
   </summary>
 </histogram>
 
+<histogram name="Signin.Intercept.Guest.Availability"
+    enum="SigninInterceptGuestAvailability" expires_after="2021-08-12">
+  <owner>rhalavati@chromium.org</owner>
+  <owner>droger@chromium.org</owner>
+  <summary>
+    Records whether Guest option was available prior to showing signin intercept
+    and if not, why.
+  </summary>
+</histogram>
+
 <histogram name="Signin.Intercept.HeuristicOutcome"
     enum="SigninInterceptHeuristicOutcome" expires_after="2021-08-12">
   <owner>droger@chromium.org</owner>