Replace FOR_EACH_OBSERVER in c/b/chromeos with range-based for

chrome/browser/chromeos/device/input_service_proxy.cc

Index: chrome/browser/chromeos/device/input_service_proxy.cc
diff --git a/chrome/browser/chromeos/device/input_service_proxy.cc b/chrome/browser/chromeos/device/input_service_proxy.cc
index 3499cd5d3852959fb5dc7b0c1cdd777234ec84de..601bc611a7298d6f64c7fe52bb863d707a86b500 100644
--- a/chrome/browser/chromeos/device/input_service_proxy.cc
+++ b/chrome/browser/chromeos/device/input_service_proxy.cc
@@ -146,12 +146,14 @@ void InputServiceProxy::SetThreadIdForTesting(BrowserThread::ID thread_id) {
 void InputServiceProxy::OnDeviceAdded(
     const InputServiceLinux::InputDeviceInfo& info) {
   DCHECK(thread_checker_.CalledOnValidThread());
-  FOR_EACH_OBSERVER(Observer, observers_, OnInputDeviceAdded(info));
+  for (auto& observer : observers_)
+    observer.OnInputDeviceAdded(info);
 }
 
 void InputServiceProxy::OnDeviceRemoved(const std::string& id) {
   DCHECK(thread_checker_.CalledOnValidThread());
-  FOR_EACH_OBSERVER(Observer, observers_, OnInputDeviceRemoved(id));
+  for (auto& observer : observers_)
+    observer.OnInputDeviceRemoved(id);
 }
 
 }  // namespace chromeos