Expose file size from log file reader classes

Change-Id: Ib826c4405ba78e9e1ab37dfd1893d67fc08a7522
Signed-off-by: James Kuszmaul <james.kuszmaul@bluerivertech.com>
diff --git a/aos/events/logging/file_operations.h b/aos/events/logging/file_operations.h
index faf63cb..538ae60 100644
--- a/aos/events/logging/file_operations.h
+++ b/aos/events/logging/file_operations.h
@@ -14,10 +14,15 @@
 // associated with either a single file or directory that contains log files.
 class FileOperations {
  public:
+  struct File {
+    std::string name;
+    size_t size;
+  };
+
   virtual ~FileOperations() = default;
 
   virtual bool Exists() = 0;
-  virtual void FindLogs(std::vector<std::string> *files) = 0;
+  virtual void FindLogs(std::vector<File> *files) = 0;
 };
 
 // Implements FileOperations with standard POSIX filesystem APIs. These work on
@@ -29,7 +34,7 @@
 
   bool Exists() override { return std::filesystem::exists(filename_); }
 
-  void FindLogs(std::vector<std::string> *files) override;
+  void FindLogs(std::vector<File> *files) override;
 
  private:
   std::string filename_;