Implement newly designed sign-in related histograms for desktop platorms.

components/signin/core/browser/signin_metrics.h

Index: components/signin/core/browser/signin_metrics.h
diff --git a/components/signin/core/browser/signin_metrics.h b/components/signin/core/browser/signin_metrics.h
index fa7242bfd4de44e57ef0118fb6cdf77e7ca6dcc4..077731978e473430bd6caf7587ea4f0cc9cd1305 100644
--- a/components/signin/core/browser/signin_metrics.h
+++ b/components/signin/core/browser/signin_metrics.h
@@ -98,22 +98,48 @@ enum {
   HISTOGRAM_CONFIRM_MAX
 };
 
-// Enum valus used with the "Signin.SigninSource" histogram, which tracks the
-// source that launched a Gaia signin page.
+// TODO(gogerald): right now, gaia server needs to distinguish the source from
+// signin_metrics::SOURCE_START_PAGE, signin_metrics::SOURCE_SETTINGS and the
+// others to show advanced sync setting, remove them after switching to Minute
+// Maid sign in flow.
 enum Source {
-  SOURCE_START_PAGE = 0, // This must be first.
-  SOURCE_NTP_LINK,
-  SOURCE_MENU,
-  SOURCE_SETTINGS,
-  SOURCE_EXTENSION_INSTALL_BUBBLE,
-  SOURCE_APP_LAUNCHER,
-  SOURCE_APPS_PAGE_LINK,
-  SOURCE_BOOKMARK_BUBBLE,
-  SOURCE_AVATAR_BUBBLE_SIGN_IN,
-  SOURCE_AVATAR_BUBBLE_ADD_ACCOUNT,
-  SOURCE_DEVICES_PAGE,
-  SOURCE_REAUTH,
-  SOURCE_UNKNOWN, // This must be last.
+  SOURCE_START_PAGE = 0,  // This must be first.
+  SOURCE_SETTINGS = 3,
+  SOURCE_OTHERS,
+};
+
+// Enum values which enumerates all access points where sign in could be
+// initiated. Not all of them exist on all platforms. They are used with
+// "Signin.SigninStartedAccessPoint" and "Signin.SigninCompletedAccessPoint"
+// histograms.
+enum AccessPoint {

[sky, 2015/12/03 22:45:28]

As you're changing all this around it would be nice if you used enum class so
that you could forward declare these and not have to include the header in all
the .h files.

[gogerald1, 2015/12/04 20:49:09]

Done.

+  ACCESS_POINT_START_PAGE = 0,
+  ACCESS_POINT_NTP_LINK,
+  ACCESS_POINT_MENU,
+  ACCESS_POINT_SETTINGS,
+  ACCESS_POINT_SUPERVISED_USER,
+  ACCESS_POINT_EXTENSION_INSTALL_BUBBLE,
+  ACCESS_POINT_EXTENSIONS,
+  ACCESS_POINT_APPS_PAGE_LINK,
+  ACCESS_POINT_BOOKMARK_BUBBLE,
+  ACCESS_POINT_BOOKMARK_MANAGER,
+  ACCESS_POINT_AVATAR_BUBBLE_SIGN_IN,
+  ACCESS_POINT_USER_MANAGER,
+  ACCESS_POINT_DEVICES_PAGE,
+  ACCESS_POINT_CLOUD_PRINT,
+  ACCESS_POINT_CONTENT_AREA,
+  ACCESS_POINT_SIGNIN_PROMO,
+  ACCESS_POINT_RECENT_TABS,
+  ACCESS_POINT_MAX  // This must be last.
+};
+
+// Enum values which enumerates all reasons to start sign in process.
+enum Reason {
+  REASON_SIGNIN_PRIMARY_ACCOUNT = 0,
+  REASON_ADD_SECONDARY_ACCOUNT,
+  REASON_REAUTHENTICATION,
+  REASON_UNLOCK,
+  REASON_MAX  // This must be last.
 };
 
 // Enum values used for use with the "Signin.Reauth" histogram.
@@ -177,6 +203,13 @@ enum AccountReconcilorState {
   ACCOUNT_RECONCILOR_HISTOGRAM_COUNT,
 };
 
+// Tracks the access point of sign in.
+void LogSigninAccessPointStarted(AccessPoint access_point);
+void LogSigninAccessPointCompleted(AccessPoint access_point);
+
+// Tracks the reason of sign in.
+void LogSigninReason(Reason reason);
+
 // Log to UMA histograms and UserCounts stats about a single execution of the
 // AccountReconciler.
 // |total_number_accounts| - How many accounts are in the browser for this
@@ -207,9 +240,6 @@ void LogSigninAccountReconciliationDuration(base::TimeDelta duration,
 // Track a successful signin.
 void LogSigninAddAccount();
 
-// Tracks the original source that showed the signin page.
-void LogSigninSource(Source source);
-
 // Track a successful signin of a profile.
 void LogSigninProfile(bool is_first_run, base::Time install_date);