firmare: start implementing session stat

Session-specific stat is a call required by the P2A bridge to allow the
host to configure its side of the equation.

Change-Id: I90570641cf9a6816fb91e8329582b882aef212cf
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/file_handler.cpp b/file_handler.cpp
index 0647b65..d47e222 100644
--- a/file_handler.cpp
+++ b/file_handler.cpp
@@ -88,4 +88,10 @@
     return true;
 }
 
+int FileHandler::getSize()
+{
+    /* TODO: implement (maybe just stat on the file). */
+    return 0;
+}
+
 } // namespace blobs