Name the crashpad handler thread

Thread names are great in general. They are specifically good when doing
multi-process debugging because the names of the main threads are the
best clue as to which process is which. The crashpad handler threads
were notably missing names in a recent debugging session. This fixes
that.

This is being done in Windows specific Chromium code because that is
where the benefit is greatest and because crashpad doesn't have a
function to set thread names.

Bug: 1004991
Change-Id: Id7163852c3a609856fc50b30932a313e3dd34a8a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1808450Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Bruce Dawson <brucedawson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#697744}

components/crash/content/app/run_as_crashpad_handler_win.cc

@@ -15,6 +15,7 @@
 #include "base/stl_util.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/threading/platform_thread.h"
 #include "components/browser_watcher/stability_report_user_stream_data_source.h"
 #include "components/gwp_asan/buildflags/buildflags.h"
 #include "third_party/crashpad/crashpad/client/crashpad_info.h"
@@ -36,6 +37,8 @@ int RunAsCrashpadHandler(const base::CommandLine& command_line,
   // processes.
   base::EnableTerminationOnOutOfMemory();
 
+  base::PlatformThread::SetName("CrashpadMainThread");
+
   // If the handler is started with --monitor-self, it'll need a ptype
   // annotation set. It'll normally set one itself by being invoked with
   // --monitor-self-annotation=ptype=crashpad-handler, but that leaves a window