Use constexpr TaskTraits constructor in components.

components/leveldb/env_mojo.cc

Index: components/leveldb/env_mojo.cc
diff --git a/components/leveldb/env_mojo.cc b/components/leveldb/env_mojo.cc
index 471f7141023731c5f8e7458d516873ae4f578036..6e6980292efae589589855fe6e556d896b633957 100644
--- a/components/leveldb/env_mojo.cc
+++ b/components/leveldb/env_mojo.cc
@@ -413,13 +413,10 @@ void MojoEnv::SleepForMicroseconds(int micros) {
 }
 
 void MojoEnv::Schedule(void (*function)(void* arg), void* arg) {
-  base::PostTaskWithTraits(
-      FROM_HERE,
-      base::TaskTraits()
-          .MayBlock()
-          .WithBaseSyncPrimitives()
-          .WithShutdownBehavior(base::TaskShutdownBehavior::BLOCK_SHUTDOWN),
-      base::Bind(function, arg));
+  base::PostTaskWithTraits(FROM_HERE,
+                           {base::MayBlock(), base::WithBaseSyncPrimitives(),
+                            base::TaskShutdownBehavior::BLOCK_SHUTDOWN},
+                           base::Bind(function, arg));
 }
 
 void MojoEnv::StartThread(void (*function)(void* arg), void* arg) {