Make Crashpad start asynchronous, and move back to chrome_elf

components/crash/content/app/crashpad_win.cc

Index: components/crash/content/app/crashpad_win.cc
diff --git a/components/crash/content/app/crashpad_win.cc b/components/crash/content/app/crashpad_win.cc
index bdbd94ee57507ef7fab4541a4615c4b6c3d0383a..cdccddf86bcbbe321a2d0552317e2b452695dd5c 100644
--- a/components/crash/content/app/crashpad_win.cc
+++ b/components/crash/content/app/crashpad_win.cc
@@ -118,9 +118,15 @@ base::FilePath PlatformCrashpadInitialization(bool initial_client,
       exe_file = exe_dir.Append(FILE_PATH_LITERAL("crashpad_handler.exe"));
     }
 
-    g_crashpad_client.Get().StartHandler(
-        exe_file, database_path, metrics_path, url, process_annotations,
-        arguments, false, false);
+    if (!g_crashpad_client.Get().StartHandler(
+            exe_file, database_path, metrics_path, url, process_annotations,
+            arguments, false, true)) {
+      // This means that CreateThread() failed, so this process is very messed
+      // up. This should be effectively unreachable. Note that if this is
+      // converted to non-fatal, calls to BlockUntilHandlerStarted() will have
+      // to be amended.
+      LOG(FATAL) << "synchronous part of handler startup failed";
+    }
 
     // If we're the browser, push the pipe name into the environment so child
     // processes can connect to it. If we inherited another crashpad_handler's
@@ -208,6 +214,15 @@ MSVC_ENABLE_OPTIMIZE()
 }  // namespace
 
 }  // namespace internal
+
+void BlockUntilHandlerStarted() {
+  // We know that the StartHandler() at least started asynchronous startup if
+  // we're here, as if it doesn't, we abort.
+  if (!internal::g_crashpad_client.Get().WaitForHandlerStart()) {
+    LOG(ERROR) << "Crashpad handler failed to start, crash reporting disabled";
+  }
+}
+
 }  // namespace crash_reporter
 
 extern "C" {