Monitor crashpad_handler for crashes [sometimes]

chrome/app/chrome_crash_reporter_client_win.cc

Index: chrome/app/chrome_crash_reporter_client_win.cc
diff --git a/chrome/app/chrome_crash_reporter_client_win.cc b/chrome/app/chrome_crash_reporter_client_win.cc
index b0ddb00c47e05443c0b180044cd5570084bf04a5..fdd21ce907bb7bee3a34ead0a8eaef112f540bc3 100644
--- a/chrome/app/chrome_crash_reporter_client_win.cc
+++ b/chrome/app/chrome_crash_reporter_client_win.cc
@@ -19,12 +19,14 @@
 #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 {
 
@@ -405,6 +407,36 @@ 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).