Removes MessageLoop::TYPE_XXX where possible

base/memory/discardable_memory_provider_unittest.cc

Index: base/memory/discardable_memory_provider_unittest.cc
diff --git a/base/memory/discardable_memory_provider_unittest.cc b/base/memory/discardable_memory_provider_unittest.cc
index 7e84dc4ac1371e2d04efe5d4938d1ca740ec6056..20507008239765fa7016aaf549a3d4b85634b137 100644
--- a/base/memory/discardable_memory_provider_unittest.cc
+++ b/base/memory/discardable_memory_provider_unittest.cc
@@ -62,8 +62,7 @@ class DiscardableMemoryProviderTestBase {
   };
 
   DiscardableMemoryProviderTestBase()
-      : message_loop_(MessageLoop::TYPE_IO),
-        provider_(new internal::DiscardableMemoryProvider) {
+      : provider_(new internal::DiscardableMemoryProvider) {
     provider_->RegisterMemoryPressureListener();
   }
 
@@ -101,7 +100,7 @@ class DiscardableMemoryProviderTestBase {
   }
 
  private:
-  MessageLoop message_loop_;
+  MessageLoopForIO message_loop_;
   scoped_ptr<internal::DiscardableMemoryProvider> provider_;
 };