Replace FOR_EACH_OBSERVER in components/drive with range-based for

components/drive/chromeos/file_system.cc

Index: components/drive/chromeos/file_system.cc
diff --git a/components/drive/chromeos/file_system.cc b/components/drive/chromeos/file_system.cc
index 0ec7d38fb35cf7cd90df29754866a5e13720cbb5..b04a84b1e86c7ea5c93678a0336df3925cbba8dc 100644
--- a/components/drive/chromeos/file_system.cc
+++ b/components/drive/chromeos/file_system.cc
@@ -824,8 +824,8 @@ void FileSystem::SearchByHashes(const std::set<std::string>& hashes,
 void FileSystem::OnFileChangedByOperation(const FileChange& changed_files) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
-  FOR_EACH_OBSERVER(
-      FileSystemObserver, observers_, OnFileChanged(changed_files));
+  for (auto& observer : observers_)
+    observer.OnFileChanged(changed_files);
 }
 
 void FileSystem::OnEntryUpdatedByOperation(const ClientContext& context,
@@ -855,9 +855,8 @@ void FileSystem::OnDriveSyncErrorAfterGetFilePath(
     FileError error) {
   if (error != FILE_ERROR_OK)
     return;
-  FOR_EACH_OBSERVER(FileSystemObserver,
-                    observers_,
-                    OnDriveSyncError(type, *file_path));
+  for (auto& observer : observers_)
+    observer.OnDriveSyncError(type, *file_path);
 }
 
 bool FileSystem::WaitForSyncComplete(const std::string& local_id,
@@ -868,15 +867,15 @@ bool FileSystem::WaitForSyncComplete(const std::string& local_id,
 void FileSystem::OnDirectoryReloaded(const base::FilePath& directory_path) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
-  FOR_EACH_OBSERVER(
-      FileSystemObserver, observers_, OnDirectoryChanged(directory_path));
+  for (auto& observer : observers_)
+    observer.OnDirectoryChanged(directory_path);
 }
 
 void FileSystem::OnFileChanged(const FileChange& changed_files) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
-  FOR_EACH_OBSERVER(
-      FileSystemObserver, observers_, OnFileChanged(changed_files));
+  for (auto& observer : observers_)
+    observer.OnFileChanged(changed_files);
 }
 
 void FileSystem::OnLoadFromServerComplete() {