arc: Logging ARC data removal reasons

chrome/browser/chromeos/arc/arc_optin_uma.cc

Index: chrome/browser/chromeos/arc/arc_optin_uma.cc
diff --git a/chrome/browser/chromeos/arc/arc_optin_uma.cc b/chrome/browser/chromeos/arc/arc_optin_uma.cc
index dfa391a8ba33100d76e3f809fdf0e34ca9cb3cce..cea4e1c4a8762618f5ec4217a37c07fd0251ae4b 100644
--- a/chrome/browser/chromeos/arc/arc_optin_uma.cc
+++ b/chrome/browser/chromeos/arc/arc_optin_uma.cc
@@ -56,4 +56,40 @@ void UpdateSilentAuthCodeUMA(OptInSilentAuthCode state) {
                             static_cast<int>(OptInSilentAuthCode::SIZE));
 }
 
+std::ostream& operator<<(std::ostream& os, const ProvisioningResult& result) {
+#define MAP_PROVISIONING_RESULT(name) \
+  case ProvisioningResult::name:      \
+    return os << #name
+
+  switch (result) {
+    MAP_PROVISIONING_RESULT(SUCCESS);
+    MAP_PROVISIONING_RESULT(UNKNOWN_ERROR);
+    MAP_PROVISIONING_RESULT(GMS_NETWORK_ERROR);
+    MAP_PROVISIONING_RESULT(GMS_SERVICE_UNAVAILABLE);
+    MAP_PROVISIONING_RESULT(GMS_BAD_AUTHENTICATION);
+    MAP_PROVISIONING_RESULT(DEVICE_CHECK_IN_FAILED);
+    MAP_PROVISIONING_RESULT(CLOUD_PROVISION_FLOW_FAILED);
+    MAP_PROVISIONING_RESULT(MOJO_VERSION_MISMATCH);
+    MAP_PROVISIONING_RESULT(MOJO_CALL_TIMEOUT);
+    MAP_PROVISIONING_RESULT(DEVICE_CHECK_IN_TIMEOUT);
+    MAP_PROVISIONING_RESULT(DEVICE_CHECK_IN_INTERNAL_ERROR);
+    MAP_PROVISIONING_RESULT(GMS_SIGN_IN_FAILED);
+    MAP_PROVISIONING_RESULT(GMS_SIGN_IN_TIMEOUT);
+    MAP_PROVISIONING_RESULT(GMS_SIGN_IN_INTERNAL_ERROR);
+    MAP_PROVISIONING_RESULT(CLOUD_PROVISION_FLOW_TIMEOUT);
+    MAP_PROVISIONING_RESULT(CLOUD_PROVISION_FLOW_INTERNAL_ERROR);
+    MAP_PROVISIONING_RESULT(ARC_STOPPED);
+    MAP_PROVISIONING_RESULT(OVERALL_SIGN_IN_TIMEOUT);
+    MAP_PROVISIONING_RESULT(CHROME_SERVER_COMMUNICATION_ERROR);
+    MAP_PROVISIONING_RESULT(SIZE);
+  }
+
+#undef MAP_PROVISIONING_RESULT
+
+  // Some compilers report an error even if all values of an enum-class are
+  // covered exhaustively in a switch statement.
+  NOTREACHED() << "Invalid value " << static_cast<int>(result);
+  return os;
+}
+
 }  // namespace arc