Enrollment recovery: Add UMA stats.

chrome/browser/ui/webui/chromeos/login/enrollment_screen_handler.cc

Index: chrome/browser/ui/webui/chromeos/login/enrollment_screen_handler.cc
diff --git a/chrome/browser/ui/webui/chromeos/login/enrollment_screen_handler.cc b/chrome/browser/ui/webui/chromeos/login/enrollment_screen_handler.cc
index b4b8f02f9f00ed226f9894681e5e5baa259c1989..0422a8397dd55a6b1f220bb363cb5de386243347 100644
--- a/chrome/browser/ui/webui/chromeos/login/enrollment_screen_handler.cc
+++ b/chrome/browser/ui/webui/chromeos/login/enrollment_screen_handler.cc
@@ -48,23 +48,11 @@ const char kEnrollmentStepSignin[] = "signin";
 const char kEnrollmentStepSuccess[] = "success";
 
 // Enrollment mode strings.
-const char kEnrollmentModeManual[] = "manual";
-const char kEnrollmentModeForced[] = "forced";
-const char kEnrollmentModeAuto[] = "auto";
+const char* const kModeStrings[EnrollmentScreenActor::ENROLLMENT_MODE_COUNT] =
+    { "manual", "forced", "auto", "recovery" };
 
 std::string EnrollmentModeToString(EnrollmentScreenActor::EnrollmentMode mode) {
-  switch (mode) {
-    case EnrollmentScreenActor::ENROLLMENT_MODE_MANUAL:
-      return kEnrollmentModeManual;
-    case EnrollmentScreenActor::ENROLLMENT_MODE_FORCED:
-      return kEnrollmentModeForced;
-    case EnrollmentScreenActor::ENROLLMENT_MODE_AUTO:
-      return kEnrollmentModeAuto;
-    default:
-      NOTREACHED() << "Bad enrollment mode " << mode;
-  }
-
-  return kEnrollmentModeManual;
+  return kModeStrings[mode];

[pastarmovj, 2014/07/14 08:46:06]

This is potentially an issue. You should not rely only on the compiler to guard
valid values of the enum. If for some reason this code should work against some
other lib/compilation unit which sees different definition of the enum you can
easily end up with out of bounds error.

I would add a CHECK on the mode here.

[Thiemo Nagel, 2014/07/14 10:30:35]

Done.

 }
 
 // A helper class that takes care of asynchronously revoking a given token.