Monitor crashpad_handler for crashes [sometimes]

chrome/app/chrome_crash_reporter_client_win.cc

 // 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.
 
 // TODO(ananta/scottmg)
 // Add test coverage for Crashpad.
 #include "chrome/app/chrome_crash_reporter_client_win.h"
 
 #include <windows.h>
 
 #include <assert.h>
 #include <shellapi.h>
 
 #include <iterator>
 #include <memory>
 #include <string>
 
 #include "base/command_line.h"
 #include "base/debug/crash_logging.h"
 #include "base/debug/leak_annotations.h"
 #include "base/format_macros.h"
+#include "base/rand_util.h"
 #include "chrome/common/chrome_result_codes.h"
 #include "chrome/install_static/install_details.h"
 #include "chrome/install_static/install_util.h"
 #include "chrome/install_static/user_data_dir.h"
 #include "components/crash/content/app/crashpad.h"
 #include "components/crash/core/common/crash_keys.h"
+#include "components/version_info/channel.h"
 
 namespace {
 
 // TODO(ananta)
 // When the new crash key map implementation lands, we should remove the
 // constants defined below, the RegisterCrashKeysHelper function, the
 // RegisterCrashKeys function in the crash_keys::CrashReporterClient interface
 // and the snprintf function defined here.
 constexpr char kActiveURL[] = "url-chunk";
 constexpr char kFontKeyName[] = "font_key_name";
@@ skipping 360 matching lines @@
 }
 
 bool ChromeCrashReporterClient::GetCollectStatsConsent() {
   return install_static::GetCollectStatsConsent();
 }
 
 bool ChromeCrashReporterClient::GetCollectStatsInSample() {
   return install_static::GetCollectStatsInSample();
 }
 
+bool ChromeCrashReporterClient::ShouldMonitorCrashHandlerExpensively() {
+  // The expensive mechanism dedicates a process to be crashpad_handler's own
+  // crashpad_handler. In Chrome builds for official release, scale back on
+  // this in the more stable channels. There's a fallback crash handler that
+  // can catch crashes when this expensive mechanism isn't used, although the
+  // fallback crash handler has different characteristics so it's desirable to
+  // use the expensive mechanism at least some of the time.
+  double probability = 0.5;
+#if defined(GOOGLE_CHROME_BUILD) && defined(OFFICIAL_BUILD)
+  switch (install_static::InstallDetails::Get().GetChannel()) {
+    case version_info::Channel::STABLE:
+      return false;
+
+    case version_info::Channel::BETA:
+      probability = 0.1;
+      break;
+
+    case version_info::Channel::DEV:
+      probability = 0.25;
+      break;
+
+    case version_info::Channel::CANARY:
+    case version_info::Channel::UNKNOWN:
+      break;
+  }
+#endif
+
+  return base::RandDouble() < probability;
+}
+
 bool ChromeCrashReporterClient::EnableBreakpadForProcess(
     const std::string& process_type) {
   // This is not used by Crashpad (at least on Windows).
   NOTREACHED();
   return true;
 }