Refactor "IsUnderDriveMountPoint" in v2 app code for generalization to non-Drive volumes.

apps/DEPS

Index: apps/DEPS
diff --git a/apps/DEPS b/apps/DEPS
index dd7ccc14410c2109b0c474280d4f67cd88e37b76..94bb1103f06b6e2a87b26a7c197eb91eb55328d5 100644
--- a/apps/DEPS
+++ b/apps/DEPS
@@ -17,7 +17,7 @@ include_rules = [
   # Temporary allowed includes.
   # TODO(benwells): remove these (http://crbug.com/159366)
   "+chrome/browser/chrome_notification_types.h",
-  "+chrome/browser/chromeos/drive",
+  "+chrome/browser/chromeos/file_manager/filesystem_api_util.h",

[mtomasz, 2014/05/26 05:54:15]

I'm not sure if file_manager is the best place for it. The File System Provider
API may be enabled on non Chrome OS platforms in the future, which do not have a
file manager. WDYT?

[kinaba, 2014/05/27 05:39:28]

I understand, but for now let me go as in the current form. The coming
implementations of the util functions anyhow needs to rely on the functionality
of fileapi_util::ConvertAbsolutePathToXXX that lies inside file_manager/. It may
be possible to factor all these things out to somewhere better, but I'd like to
do it as a separate refactoring task (probably after we've decided how to port
FSP API to platforms without file manager.)

[mtomasz, 2014/05/27 05:40:18]

Sounds like a good plan.

   "+chrome/browser/chromeos/login/users/user_manager.h",
   "+chrome/browser/lifetime/application_lifetime.h",
   "+chrome/browser/profiles",