Enable size_t to int truncation warnings in PPAPI

ppapi/proxy/file_ref_resource.cc

Index: ppapi/proxy/file_ref_resource.cc
diff --git a/ppapi/proxy/file_ref_resource.cc b/ppapi/proxy/file_ref_resource.cc
index 098ef5f336abfccdee12abc903e012e789942b89..1d31d5ce5f1103796cd9cec1ad2b1ba0f6384741 100644
--- a/ppapi/proxy/file_ref_resource.cc
+++ b/ppapi/proxy/file_ref_resource.cc
@@ -29,7 +29,7 @@ FileRefResource::FileRefResource(
   if (uses_internal_paths()) {
     // If path ends with a slash, then normalize it away unless path is
     // the root path.
-    int path_size = create_info_.internal_path.size();
+    int path_size = static_cast<int>(create_info_.internal_path.size());

[dmichael (off chromium), 2015/02/12 18:56:43]

nit: may be a good idea to use checked_cast for type conversions that may
overflow (but admittedly it's super unlikely here)

     if (path_size > 1 && create_info_.internal_path.at(path_size - 1) == '/')
       create_info_.internal_path.erase(path_size - 1, 1);