Use a valid /prefetch argument when launching a process.

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 1628ab6a9d5cbfc1f8945e24cdee952fea8f4a2c..3729467ebb88b700da33bc98aaec099cf6039d6f 100644
--- a/components/crash/content/app/crashpad_win.cc
+++ b/components/crash/content/app/crashpad_win.cc
@@ -16,6 +16,7 @@
 #include "base/strings/utf_string_conversions.h"
 #include "build/build_config.h"
 #include "components/crash/content/app/crash_reporter_client.h"
+#include "components/startup_metric_utils/common/pre_read_field_trial_utils_win.h"
 #include "third_party/crashpad/crashpad/client/crashpad_client.h"
 #include "third_party/crashpad/crashpad/client/crashpad_info.h"
 #include "third_party/crashpad/crashpad/client/simulate_crash_win.h"
@@ -84,6 +85,15 @@ base::FilePath PlatformCrashpadInitialization(bool initial_client,
       exe_file = exe_dir.Append(FILE_PATH_LITERAL("crashpad_handler.exe"));
     } else {
       arguments.push_back("--type=crashpad-handler");
+
+      if (startup_metric_utils::GetPreReadOptions().use_prefetch_argument) {
+        // Add a prefetch argument to prevent the crashpad process from
+        // polluting the prefetch profile of the browser process.  The prefetch
+        // argument must be equal to switches::kPrefetchArgumentOther.
+        // Unfortunately, crashpad cannot depend on any of the targets that
+        // define this constant.
+        arguments.push_back("/prefetch:8");
+      }
     }
 
     // TODO(scottmg): See https://crashpad.chromium.org/bug/23.