[extensions] Replace MessageLoopProxy usage with ThreadTaskRunnerHandle

extensions/common/one_shot_event_unittest.cc

Index: extensions/common/one_shot_event_unittest.cc
diff --git a/extensions/common/one_shot_event_unittest.cc b/extensions/common/one_shot_event_unittest.cc
index 4009a0106a2d7d31ded99a22357f7a8c3448fc93..c19b036609e8f27b2df72977b84f5f49ce0ee960 100644
--- a/extensions/common/one_shot_event_unittest.cc
+++ b/extensions/common/one_shot_event_unittest.cc
@@ -6,6 +6,7 @@
 
 #include "base/bind.h"
 #include "base/run_loop.h"
+#include "base/single_thread_task_runner.h"
 #include "base/test/test_simple_task_runner.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ -76,7 +77,7 @@ TEST(OneShotEventTest, PostDefaultsToCurrentMessageLoop) {
 
 void CheckSignaledAndPostIncrement(
     OneShotEvent* event,
-    const scoped_refptr<base::TaskRunner>& runner,
+    const scoped_refptr<base::SingleThreadTaskRunner>& runner,
     int* i) {
   EXPECT_TRUE(event->is_signaled());
   event->Post(FROM_HERE, base::Bind(&Increment, i), runner);