Replicate LayoutTestRuntimeFlags across secondary window renderers.

components/test_runner/test_runner.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/test_runner/test_runner.h"
 
 #include <stddef.h>
 #include <limits>
 #include <utility>
 
@@ skipping 1834 matching lines @@
     return;
   }
 
   test_runner::DumpPixelsAsync(web_view_, layout_test_runtime_flags_,
                                delegate_->GetDeviceScaleFactorForTest(),
                                callback);
 }
 
 void TestRunner::ReplicateLayoutTestRuntimeFlagsChanges(
     const base::DictionaryValue& changed_values) {
+  DCHECK(test_is_running_);
   layout_test_runtime_flags_.tracked_dictionary().ApplyUntrackedChanges(
       changed_values);
 }
 
 bool TestRunner::HasCustomTextDump(std::string* custom_text_dump) const {
   if (shouldDumpAsCustomText()) {
     *custom_text_dump = customDumpText();
     return true;
   }
 
@@ skipping 1411 matching lines @@
 }
 
 void TestRunner::DidLosePointerLockInternal() {
   bool was_locked = pointer_locked_;
   pointer_locked_ = false;
   if (was_locked)
     web_view_->didLosePointerLock();
 }
 
 }  // namespace test_runner