chrome_paths: refactor and sanitize cache directory handling

base/path_service.cc

Index: base/path_service.cc
diff --git a/base/path_service.cc b/base/path_service.cc
index 9eed56d9513408f911e21fdb36a6b5f714a53906..8660c424c77cbdb24a853925dce249a2ae27ed45 100644
--- a/base/path_service.cc
+++ b/base/path_service.cc
@@ -215,14 +215,6 @@ bool PathService::Get(int key, std::wstring* result) {
 }
 #endif
 
-// TODO(evan): remove me -- see comments in header.
-bool PathService::IsOverridden(int key) {
-  PathData* path_data = GetPathData();
-  DCHECK(path_data);
-  AutoLock scoped_lock(path_data->lock);
-  return path_data->overrides.find(key) != path_data->overrides.end();
-}
-
 bool PathService::Override(int key, const FilePath& path) {
   PathData* path_data = GetPathData();
   DCHECK(path_data);