Clarify and separate the concept of "Drive path" and "Filesystem relative path".

Clarify and separate the concept of "Drive path" and "Filesystem relative path".

- RelativeFileSystemPath (also called VirtualPath) is the path appended
in the filesystem URL, after .../external/. So it looks like
"drive-xxx/root/foo/bar" or "Downloads-xxx/foo/bar".
Note that in the Drive case, it begins with the mount point name,
that differs from profile to profile.

- DrivePath is the path in the hierarchy we manage in drive::ResourceMetadata.
It is like "drive/root/foo/bar" and always begins with "drive".

Every path comes from drive::FileSystem is in DrivePath.
Every path that will be the part of FileSystem API must be in RelativeFileSystemPath.
We need proper conversion for the bridging codes.

BUG=337095
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=247561

[kinaba, 2014-01-27 09:05:56]

+hirono: ptal.

It's like a brain teaser but I want you (and me myself) to know these
very well, in order not to mix them inappropriately.
Feel free to request clarification to me if you have any questions.

[hirono, 2014-01-27 11:09:13]

On 2014/01/27 09:05:56, kinaba wrote:
> +hirono: ptal.
> 
> It's like a brain teaser but I want you (and me myself) to know these
> very well, in order not to mix them inappropriately.
> Feel free to request clarification to me if you have any questions.

Thanks!
Maybe we should use Filesystem URLs to communicate with the JavaScript side.
Filesystem relative paths are needed for now, but after JavaScript side handles
the URLs, we can replace them with URLs and save the number of path types.
WDYT?

[kinaba, 2014-01-27 11:42:30]

On 2014/01/27 11:09:13, hirono wrote:
> On 2014/01/27 09:05:56, kinaba wrote:
> > +hirono: ptal.
> > 
> > It's like a brain teaser but I want you (and me myself) to know these
> > very well, in order not to mix them inappropriately.
> > Feel free to request clarification to me if you have any questions.
> 
> Thanks!
> Maybe we should use Filesystem URLs to communicate with the JavaScript side.
> Filesystem relative paths are needed for now, but after JavaScript side
handles
> the URLs, we can replace them with URLs and save the number of path types.
> WDYT?

I agree, and I think that (use URL everywhere) is the next separate step after
this CL.
The current CL eliminates all wrong mention to "relative path" that was in
reality a "drive path".

Now we use "relative path" only at one kind of place: API callback that takes
Entry object,
and thus the coming interface changing patch can concentrate on the interface
conversion. WDYT?

[hirono, 2014-01-27 11:49:44]

On 2014/01/27 11:42:30, kinaba wrote:
> On 2014/01/27 11:09:13, hirono wrote:
> > On 2014/01/27 09:05:56, kinaba wrote:
> > > +hirono: ptal.
> > > 
> > > It's like a brain teaser but I want you (and me myself) to know these
> > > very well, in order not to mix them inappropriately.
> > > Feel free to request clarification to me if you have any questions.
> > 
> > Thanks!
> > Maybe we should use Filesystem URLs to communicate with the JavaScript side.
> > Filesystem relative paths are needed for now, but after JavaScript side
> handles
> > the URLs, we can replace them with URLs and save the number of path types.
> > WDYT?
> 
> I agree, and I think that (use URL everywhere) is the next separate step after
> this CL.
> The current CL eliminates all wrong mention to "relative path" that was in
> reality a "drive path".
> 
> Now we use "relative path" only at one kind of place: API callback that takes
> Entry object,
> and thus the coming interface changing patch can concentrate on the interface
> conversion. WDYT?

Thanks! lgtm!

[commit-bot: I haz the power, 2014-01-28 06:33:34]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/kinaba@chromium.org/147993003/1

[commit-bot: I haz the power, 2014-01-28 19:28:26]

Retried try job too often on mac_rel for step(s) app_list_unittests,
base_unittests, browser_tests, cacheinvalidation_unittests, cc_unittests,
check_deps, check_deps2git, chromedriver_unittests, components_unittests,
content_browsertests, content_unittests, crypto_unittests,
google_apis_unittests, gpu_unittests, interactive_ui_tests, ipc_tests,
jingle_unittests, media_unittests, message_center_unittests, nacl_integration,
net_unittests, ppapi_unittests, printing_unittests, remoting_unittests,
sql_unittests, sync_integration_tests, sync_unit_tests,
telemetry_perf_unittests, telemetry_unittests, unit_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=mac_rel&nu...

[commit-bot: I haz the power, 2014-01-28 21:29:39]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/kinaba@chromium.org/147993003/1

[commit-bot: I haz the power, 2014-01-29 01:16:49]

Change committed as 247561