Monitor crashpad_handler for crashes [sometimes]

components/crash/content/app/crashpad_mac.mm

Index: components/crash/content/app/crashpad_mac.mm
diff --git a/components/crash/content/app/crashpad_mac.mm b/components/crash/content/app/crashpad_mac.mm
index 2cabccb88d19c655afe3248ad10a3086b0afddce..7880f7e437c72a3887a256f9b44f79b1bed15f36 100644
--- a/components/crash/content/app/crashpad_mac.mm
+++ b/components/crash/content/app/crashpad_mac.mm
@@ -81,6 +81,16 @@
       process_annotations["plat"] = std::string("OS X");
 
       std::vector<std::string> arguments;
+
+      if (crash_reporter_client->ShouldMonitorCrashHandlerExpensively()) {
+        arguments.push_back("--monitor-self");
+      }
+
+      // Set up --monitor-self-annotation even in the absence of --monitor-self
+      // so that minidumps produced by generate_dump will contain these
+      // annotations.
+      arguments.push_back("--monitor-self-annotation=ptype=crashpad-handler");
+
       if (!browser_process) {
         // If this is an initial client that's not the browser process, it's
         // important that the new Crashpad handler also not be connected to any