Reduce usage of FOR_EACH_OBSERVER macro in base

base/memory/memory_pressure_listener.cc

Index: base/memory/memory_pressure_listener.cc
diff --git a/base/memory/memory_pressure_listener.cc b/base/memory/memory_pressure_listener.cc
index 11859ada613f77cd9418e87351d17c2f948589b2..27e700189bd32363e62b8ddd1f4b9e5567dc0112 100644
--- a/base/memory/memory_pressure_listener.cc
+++ b/base/memory/memory_pressure_listener.cc
@@ -38,8 +38,8 @@ class MemoryPressureObserver {
     async_observers_->Notify(FROM_HERE,
         &MemoryPressureListener::Notify, memory_pressure_level);
     AutoLock lock(sync_observers_lock_);
-    FOR_EACH_OBSERVER(MemoryPressureListener, *sync_observers_,
-        MemoryPressureListener::SyncNotify(memory_pressure_level));
+    for (auto& observer : *sync_observers_)
+      observer.MemoryPressureListener::SyncNotify(memory_pressure_level);
   }
 
  private: