Monitor crashpad_handler for crashes [sometimes]

chrome/app/chrome_crash_reporter_client_mac.mm

 // Copyright 2013 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 "chrome/app/chrome_crash_reporter_client.h"
 
 #include <CoreFoundation/CoreFoundation.h>
 
 #include "base/mac/scoped_cftyperef.h"
 #include "base/path_service.h"
+#include "base/rand_util.h"
 #include "base/strings/sys_string_conversions.h"
+#include "chrome/common/channel_info.h"
 #include "chrome/common/chrome_paths.h"
 #include "components/policy/policy_constants.h"
+#include "components/version_info/version_info.h"
 
 #if !defined(DISABLE_NACL)
 #include "base/command_line.h"
 #include "chrome/common/chrome_switches.h"
 #include "components/nacl/common/nacl_switches.h"
 #include "native_client/src/trusted/service_runtime/osx/crash_filter.h"
 #endif
 
 bool ChromeCrashReporterClient::GetCrashMetricsLocation(
     base::FilePath* metrics_dir) {
   return PathService::Get(chrome::DIR_USER_DATA, metrics_dir);
 }
 
 bool ChromeCrashReporterClient::ReportingIsEnforcedByPolicy(
     bool* breakpad_enabled) {
   base::ScopedCFTypeRef<CFStringRef> key(
       base::SysUTF8ToCFStringRef(policy::key::kMetricsReportingEnabled));
   Boolean key_valid;
   Boolean metrics_reporting_enabled = CFPreferencesGetAppBooleanValue(key,
       kCFPreferencesCurrentApplication, &key_valid);
   if (key_valid &&
       CFPreferencesAppValueIsForced(key, kCFPreferencesCurrentApplication)) {
     *breakpad_enabled = metrics_reporting_enabled;
     return true;
   }
   return false;
 }
+
+bool ChromeCrashReporterClient::ShouldMonitorCrashHandlerExpensively() {
+  // This mechanism dedicates a process to be crashpad_handler's own
+  // crashpad_handler. In Google Chrome, scale back on this in the more stable
+  // channels. Other builds are of more of a developmental nature, so always
+  // enable the additional crash reporting.
+  double probability;
+  switch (chrome::GetChannel()) {
+    case version_info::Channel::STABLE:
+      probability = 0.01;
+      break;
+
+    case version_info::Channel::BETA:
+      probability = 0.1;
+      break;
+
+    case version_info::Channel::DEV:
+      probability = 0.25;
+      break;
+
+    default:
+      return true;
+  }
+
+  return base::RandDouble() < probability;
+}