TestBlinkWebUnitTestSupport to create the scheduler on the main thread

content/test/test_blink_web_unit_test_support.cc

 // Copyright 2013 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 "content/test/test_blink_web_unit_test_support.h"
 
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
@@ skipping 46 matching lines @@
   // Create an anonymous stats table since we don't need to share between
   // processes.
   stats_table_.reset(
       new base::StatsTable(base::StatsTable::TableIdentifier(), 20, 200));
   base::StatsTable::set_current(stats_table_.get());
 
 #ifdef V8_USE_EXTERNAL_STARTUP_DATA
   gin::IsolateHolder::LoadV8Snapshot();
 #endif
 
+  if (base::MessageLoopProxy::current()) {

[Sami, 2015/02/02 14:28:33]

Is this ever going to be false?

[alex clarke (OOO till 29th), 2015/02/02 14:30:06]

Yes. The UnitTestTestSuite uses this but (unlike blink::TestEnvironment) it
doesn't create a message loop.

+    renderer_scheduler_ = RendererScheduler::Create();
+    web_scheduler_.reset(new WebSchedulerImpl(renderer_scheduler_.get()));
+  }
+
   blink::initialize(this);
   blink::mainThreadIsolate()->SetCounterFunction(
       base::StatsTable::FindLocation);
   blink::setLayoutTestMode(true);
   blink::WebSecurityPolicy::registerURLSchemeAsLocal(
       blink::WebString::fromUTF8("test-shell-resource"));
   blink::WebSecurityPolicy::registerURLSchemeAsNoAccess(
       blink::WebString::fromUTF8("test-shell-resource"));
   blink::WebSecurityPolicy::registerURLSchemeAsDisplayIsolated(
       blink::WebString::fromUTF8("test-shell-resource"));
@@ skipping 238 matching lines @@
   return blink::WebData(buffer.data(), buffer.size());
 }
 
 bool TestBlinkWebUnitTestSupport::getBlobItems(
     const blink::WebString& uuid,
     blink::WebVector<blink::WebBlobData::Item*>* items) {
   return blob_registry_.GetBlobItems(uuid, items);
 }
 
 blink::WebScheduler* TestBlinkWebUnitTestSupport::scheduler() {
-  // Lazily create the WebSchedulerImpl and RendererScheduler if needed.
-  if (!web_scheduler_) {
-    if (!renderer_scheduler_)
-      renderer_scheduler_ = RendererScheduler::Create();
-    web_scheduler_.reset(new WebSchedulerImpl(renderer_scheduler_.get()));
-  }
   return web_scheduler_.get();
 }
 
 }  // namespace content