arc: Use FOR_EACH_OBSERVER in InstanceHolder

components/arc/instance_holder.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_ARC_INSTANCE_HOLDER_H_
 #define COMPONENTS_ARC_INSTANCE_HOLDER_H_
 
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 50 matching lines @@
   }
 
   // Called when the channel is closed.
   void CloseChannel() {
     if (!ptr_)
       return;
 
     ptr_.reset();
     raw_ptr_ = nullptr;
     version_ = 0;
-    if (observer_list_.might_have_observers()) {
-      typename base::ObserverList<Observer>::Iterator it(&observer_list_);
-      Observer* obs;
-      while ((obs = it.GetNext()) != nullptr)
-        obs->OnInstanceClosed();
-    }
+    FOR_EACH_OBSERVER(Observer, observer_list_, OnInstanceClosed());
   }
 
   // Sets the interface pointer to |ptr|, once the version is determined. This
   // will eventually invoke SetInstance(), which will notify the observers.
   void OnInstanceReady(mojo::InterfacePtr<T> ptr) {
     temporary_ptr_ = std::move(ptr);
     temporary_ptr_.QueryVersion(base::Bind(&InstanceHolder<T>::OnVersionReady,
                                            weak_factory_.GetWeakPtr()));
   }
 
   // This method is not intended to be called directly. Normally it is called by
   // OnInstanceReady once the version of the instance is determined, but it is
   // also exposed so that tests can directly inject a raw pointer+version
   // combination.
   void SetInstance(T* raw_ptr, uint32_t raw_version = T::Version_) {
     raw_ptr_ = raw_ptr;
     version_ = raw_version;
-    if (observer_list_.might_have_observers()) {
-      typename base::ObserverList<Observer>::Iterator it(&observer_list_);
-      Observer* obs;
-      while ((obs = it.GetNext()) != nullptr)
-        obs->OnInstanceReady();
-    }
+    FOR_EACH_OBSERVER(Observer, observer_list_, OnInstanceReady());
   }
 
  private:
   void OnVersionReady(uint32_t version) {
     ptr_ = std::move(temporary_ptr_);
     ptr_.set_connection_error_handler(base::Bind(
         &InstanceHolder<T>::CloseChannel, weak_factory_.GetWeakPtr()));
     SetInstance(ptr_.get(), version);
   }
 
@@ skipping 18 matching lines @@
   // This needs to be the last member in order to cancel all inflight callbacks
   // before destroying any other members.
   base::WeakPtrFactory<InstanceHolder<T>> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(InstanceHolder<T>);
 };
 
 }  // namespace arc
 
 #endif  // COMPONENTS_ARC_INSTANCE_HOLDER_H_