Update crashpad_handler man page to document all options

handler/mac/crash_report_upload_thread.cc

 // Copyright 2015 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 208 matching lines @@
       return;
     }
   }
 }
 
 void CrashReportUploadThread::ProcessPendingReport(
     const CrashReportDatabase::Report& report) {
   Settings* const settings = database_->GetSettings();
 
   bool uploads_enabled;
-  if (!settings->GetUploadsEnabled(&uploads_enabled) || !uploads_enabled) {
-    // If uploads are disabled or the upload-enabled state can’t be determined,
-    // don’t attempt to upload the new report.
+  if (!settings->GetUploadsEnabled(&uploads_enabled) ||
+      !uploads_enabled ||
+      url_.empty()) {
+    // If the upload-enabled state can’t be determined, uploads are disabled, or
+    // there’s no URL to upload to, don’t attempt to upload the new report.
     database_->SkipReportUpload(report.uuid);
     return;
   }
 
   // This currently implements very simplistic rate-limiting, compatible with
   // the Breakpad client, where the strategy is to permit one upload attempt per
   // hour, and retire reports that would exceed this limit or for which the
   // upload fails on the first attempt.
   //
   // TODO(mark): Provide a proper rate-limiting strategy and allow for failed
@@ skipping 118 matching lines @@
 }
 
 // static
 void* CrashReportUploadThread::RunThreadMain(void* arg) {
   CrashReportUploadThread* self = static_cast<CrashReportUploadThread*>(arg);
   self->ThreadMain();
   return nullptr;
 }
 
 }  // namespace crashpad