diff --git a/tools/wptrunner/wptrunner/browsers/chrome.py b/tools/wptrunner/wptrunner/browsers/chrome.py
index b39b8deb76c958..73b3b5344b8125 100644
--- a/tools/wptrunner/wptrunner/browsers/chrome.py
+++ b/tools/wptrunner/wptrunner/browsers/chrome.py
@@ -67,13 +67,10 @@ def browser_kwargs(logger, test_type, run_info_data, config, **kwargs):
 
 def executor_kwargs(logger, test_type, test_environment, run_info_data, subsuite,
                     **kwargs):
-    sanitizer_enabled = kwargs.get("sanitizer_enabled")
-    if sanitizer_enabled:
-        test_type = "crashtest"
     executor_kwargs = base_executor_kwargs(test_type, test_environment, run_info_data,
                                            subsuite, **kwargs)
     executor_kwargs["close_after_done"] = True
-    executor_kwargs["sanitizer_enabled"] = sanitizer_enabled
+    executor_kwargs["sanitizer_enabled"] = kwargs.get("sanitizer_enabled", False)
     executor_kwargs["reuse_window"] = kwargs.get("reuse_window", False)
 
     capabilities = {
diff --git a/tools/wptrunner/wptrunner/executors/executorchrome.py b/tools/wptrunner/wptrunner/executors/executorchrome.py
index fa593ce4023106..e92d45094d1571 100644
--- a/tools/wptrunner/wptrunner/executors/executorchrome.py
+++ b/tools/wptrunner/wptrunner/executors/executorchrome.py
@@ -6,14 +6,10 @@
 import re
 import time
 import uuid
-from typing import Mapping, MutableMapping, Type
+from typing import Mapping, MutableMapping
 
 from webdriver import error
 
-from .base import (
-    CrashtestExecutor,
-    TestharnessExecutor,
-)
 from .executorwebdriver import (
     WebDriverBaseProtocolPart,
     WebDriverCrashtestExecutor,
@@ -29,41 +25,6 @@
 here = os.path.dirname(__file__)
 
 
-def make_sanitizer_mixin(crashtest_executor_cls: Type[CrashtestExecutor]):  # type: ignore[no-untyped-def]
-    class SanitizerMixin:
-        def __new__(cls, logger, browser, **kwargs):
-            # Overriding `__new__` is the least worst way we can force tests to run
-            # as crashtests at runtime while still supporting:
-            #   * Class attributes (e.g., `extra_timeout`)
-            #   * Pickleability for `multiprocessing` transport
-            #   * The `__wptrunner__` product interface
-            #
-            # These requirements rule out approaches with `functools.partial(...)`
-            # or global variables.
-            if kwargs.get("sanitizer_enabled"):
-                executor = crashtest_executor_cls(logger, browser, **kwargs)
-
-                def convert_from_crashtest_result(test, result):
-                    if issubclass(cls, TestharnessExecutor):
-                        status = result["status"]
-                        if status == "PASS":
-                            status = "OK"
-                        harness_result = test.make_result(status, result["message"])
-                        # Don't report subtests.
-                        return harness_result, []
-                    # `crashtest` statuses are a subset of `(print-)reftest`
-                    # ones, so no extra conversion necessary.
-                    return cls.convert_result(executor, test, result)
-
-                executor.convert_result = convert_from_crashtest_result
-                return executor
-            return super().__new__(cls)
-    return SanitizerMixin
-
-
-_SanitizerMixin = make_sanitizer_mixin(WebDriverCrashtestExecutor)
-
-
 class ChromeDriverBaseProtocolPart(WebDriverBaseProtocolPart):
     def create_window(self, type="tab", **kwargs):
         try:
@@ -211,7 +172,7 @@ def __init__(self, executor, browser, capabilities, **kwargs):
         super().__init__(executor, browser, capabilities, **kwargs)
 
 
-def _evaluate_leaks(executor_cls):
+def _evaluate_sanitized_result(executor_cls):
     if hasattr(executor_cls, "base_convert_result"):
         # Don't wrap more than once, which can cause unbounded recursion.
         return executor_cls
@@ -226,28 +187,42 @@ def convert_result(self, test, result, **kwargs):
                                            test_result.extra,
                                            test_result.stack,
                                            test_result.known_intermittent)
+        if self.sanitizer_enabled:
+            # Coerce functional failures to OK/PASS, and discard any subtest results.
+            if test_result.status in {"ERROR", "FAIL", "INTERNAL-ERROR", "PRECONDITION_FAILED"}:
+                test_result.status = test_result.default_expected
+            return test_result, []
         return test_result, subtest_results
 
     executor_cls.convert_result = convert_result
     return executor_cls
 
 
-@_evaluate_leaks
+@_evaluate_sanitized_result
 class ChromeDriverCrashTestExecutor(WebDriverCrashtestExecutor):
     protocol_cls = ChromeDriverProtocol
 
+    def __init__(self, *args, sanitizer_enabled=False, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.sanitizer_enabled = sanitizer_enabled
+
 
-@_evaluate_leaks
-class ChromeDriverRefTestExecutor(WebDriverRefTestExecutor, _SanitizerMixin):  # type: ignore
+@_evaluate_sanitized_result
+class ChromeDriverRefTestExecutor(WebDriverRefTestExecutor):
     protocol_cls = ChromeDriverProtocol
 
+    def __init__(self, *args, sanitizer_enabled=False, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.sanitizer_enabled = sanitizer_enabled
 
-@_evaluate_leaks
-class ChromeDriverTestharnessExecutor(WebDriverTestharnessExecutor, _SanitizerMixin):  # type: ignore
+
+@_evaluate_sanitized_result
+class ChromeDriverTestharnessExecutor(WebDriverTestharnessExecutor):
     protocol_cls = ChromeDriverProtocol
 
-    def __init__(self, *args, reuse_window=False, **kwargs):
+    def __init__(self, *args, sanitizer_enabled=False, reuse_window=False, **kwargs):
         super().__init__(*args, **kwargs)
+        self.sanitizer_enabled = sanitizer_enabled
         self.reuse_window = reuse_window
 
     def get_or_create_test_window(self, protocol):
@@ -284,7 +259,10 @@ def _get_next_message_classic(self, protocol, url, test_window):
             raise
 
 
-@_evaluate_leaks
-class ChromeDriverPrintRefTestExecutor(WebDriverPrintRefTestExecutor,
-                                       _SanitizerMixin):  # type: ignore
+@_evaluate_sanitized_result
+class ChromeDriverPrintRefTestExecutor(WebDriverPrintRefTestExecutor):
     protocol_cls = ChromeDriverProtocol
+
+    def __init__(self, *args, sanitizer_enabled=False, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.sanitizer_enabled = sanitizer_enabled
diff --git a/tools/wptrunner/wptrunner/executors/executoredge.py b/tools/wptrunner/wptrunner/executors/executoredge.py
index 95b40bd8db14f6..2ddfdb3ad8f47a 100644
--- a/tools/wptrunner/wptrunner/executors/executoredge.py
+++ b/tools/wptrunner/wptrunner/executors/executoredge.py
@@ -3,31 +3,25 @@
 import os
 
 from .executorwebdriver import (
-    WebDriverCrashtestExecutor,
     WebDriverRefTestExecutor,
     WebDriverRun,
     WebDriverTestharnessExecutor,
 )
 
-from .executorchrome import (
-    ChromeDriverProtocol,
-    make_sanitizer_mixin,
-)
+from .executorchrome import ChromeDriverProtocol
 
 here = os.path.dirname(__file__)
 
-_SanitizerMixin = make_sanitizer_mixin(WebDriverCrashtestExecutor)
-
 
 class EdgeDriverProtocol(ChromeDriverProtocol):
     vendor_prefix = "ms"
 
 
-class EdgeDriverRefTestExecutor(WebDriverRefTestExecutor, _SanitizerMixin):  # type: ignore
+class EdgeDriverRefTestExecutor(WebDriverRefTestExecutor):
     protocol_cls = EdgeDriverProtocol
 
 
-class EdgeDriverTestharnessExecutor(WebDriverTestharnessExecutor, _SanitizerMixin):  # type: ignore
+class EdgeDriverTestharnessExecutor(WebDriverTestharnessExecutor):
     protocol_cls = EdgeDriverProtocol