Improve GCM enum switch type safety

google_apis/gcm/engine/unregistration_request.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "google_apis/gcm/engine/unregistration_request.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/location.h"
@@ skipping 18 matching lines @@
 const char kRequestContentType[] = "application/x-www-form-urlencoded";
 
 // Request constants.
 const char kCategoryKey[] = "app";
 const char kSubtypeKey[] = "X-subtype";
 const char kDeleteKey[] = "delete";
 const char kDeleteValue[] = "true";
 const char kDeviceIdKey[] = "device";
 const char kLoginHeader[] = "AidLogin";
 
+// Determines whether to retry based on the status of the last request.
+bool ShouldRetryWithStatus(UnregistrationRequest::Status status) {
+  switch (status) {
+    case UnregistrationRequest::URL_FETCHING_FAILED:
+    case UnregistrationRequest::NO_RESPONSE_BODY:
+    case UnregistrationRequest::RESPONSE_PARSING_FAILED:
+    case UnregistrationRequest::INCORRECT_APP_ID:
+    case UnregistrationRequest::SERVICE_UNAVAILABLE:
+    case UnregistrationRequest::INTERNAL_SERVER_ERROR:
+    case UnregistrationRequest::HTTP_NOT_OK:
+      return true;
+    case UnregistrationRequest::SUCCESS:
+    case UnregistrationRequest::INVALID_PARAMETERS:
+    case UnregistrationRequest::UNKNOWN_ERROR:
+    case UnregistrationRequest::REACHED_MAX_RETRIES:
+      return false;
+    case UnregistrationRequest::UNREGISTRATION_STATUS_COUNT:
+      NOTREACHED();
+      break;
+  }
+  return false;
+}
+
 }  // namespace
 
 UnregistrationRequest::RequestInfo::RequestInfo(uint64_t android_id,
                                                 uint64_t security_token,
                                                 const std::string& category,
                                                 const std::string& subtype)
     : android_id(android_id),
       security_token(security_token),
       category(category),
       subtype(subtype) {
@@ skipping 121 matching lines @@
   DCHECK(!weak_ptr_factory_.HasWeakPtrs());
   base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
       FROM_HERE,
       base::Bind(&UnregistrationRequest::Start, weak_ptr_factory_.GetWeakPtr()),
       backoff_entry_.GetTimeUntilRelease());
 }
 
 void UnregistrationRequest::OnURLFetchComplete(const net::URLFetcher* source) {
   UnregistrationRequest::Status status = ParseResponse(source);
 
-  DVLOG(1) << "UnregistrationRequestStauts: " << status;
+  DVLOG(1) << "UnregistrationRequestStatus: " << status;
 
   DCHECK(custom_request_handler_.get());
   custom_request_handler_->ReportUMAs(
       status,
       backoff_entry_.failure_count(),
       base::TimeTicks::Now() - request_start_time_);
 
   recorder_->RecordUnregistrationResponse(request_info_.app_id(),
                                           source_to_record_, status);
 
-  if (status == URL_FETCHING_FAILED ||
-      status == HTTP_NOT_OK ||
-      status == NO_RESPONSE_BODY ||
-      status == SERVICE_UNAVAILABLE ||
-      status == INTERNAL_SERVER_ERROR ||
-      status == INCORRECT_APP_ID ||
-      status == RESPONSE_PARSING_FAILED) {
+  if (ShouldRetryWithStatus(status)) {
     if (retries_left_ > 0) {
       RetryWithBackoff();
       return;
     }
 
     status = REACHED_MAX_RETRIES;
     recorder_->RecordUnregistrationResponse(request_info_.app_id(),
                                             source_to_record_, status);
 
     // Only REACHED_MAX_RETRIES is reported because the function will skip
     // reporting count and time when status is not SUCCESS.
     DCHECK(custom_request_handler_.get());
     custom_request_handler_->ReportUMAs(status, 0, base::TimeDelta());
   }
 
-  // status == SUCCESS || INVALID_PARAMETERS || UNKNOWN_ERROR ||
-  //           REACHED_MAX_RETRIES
-
   callback_.Run(status);
 }
 
 }  // namespace gcm