Remove all remaining traces of MessageLoopProxy.

content/shell/browser/layout_test/layout_test_browser_context.cc

Index: content/shell/browser/layout_test/layout_test_browser_context.cc
diff --git a/content/shell/browser/layout_test/layout_test_browser_context.cc b/content/shell/browser/layout_test/layout_test_browser_context.cc
index ff55d44548ad12f6bc083e97e6ac370dccb56dd1..e5adfbfba5968088cab3f767ce63dff18d45d5b4 100644
--- a/content/shell/browser/layout_test/layout_test_browser_context.cc
+++ b/content/shell/browser/layout_test/layout_test_browser_context.cc
@@ -73,7 +73,7 @@ class MojomProtocolHandler : public net::URLRequestJobFactory::ProtocolHandler {
 
     return new net::URLRequestFileJob(
         request, network_delegate, path,
-        BrowserThread::GetMessageLoopProxyForThread(BrowserThread::FILE));
+        BrowserThread::GetTaskRunnerForThread(BrowserThread::FILE));
   }
 };
 
@@ -96,8 +96,8 @@ LayoutTestBrowserContext::CreateURLRequestContextGetter(
       "layout-test-mojom", make_linked_ptr(new MojomProtocolHandler)));
   return new LayoutTestURLRequestContextGetter(
       ignore_certificate_errors(), GetPath(),
-      BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO),
-      BrowserThread::GetMessageLoopProxyForThread(BrowserThread::FILE),
+      BrowserThread::GetTaskRunnerForThread(BrowserThread::IO),
+      BrowserThread::GetTaskRunnerForThread(BrowserThread::FILE),
       protocol_handlers, std::move(request_interceptors), net_log());
 }