Add GetChangelist operation for Drive V2.

Add GetChangelist operation for Drive V2.

This CL adds GetChangelist operation and its corresponding interface
for DocumentsService.  No code uses this interface yet.

BUG=chromium:127728
TEST=none

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=150322

[kochi, 2012-08-07 07:13:26]

Ryo,

Could you review this?
Thanks,

[hashimoto, 2012-08-07 07:36:57]

https://chromiumcodereview.appspot.com/10836125/diff/2001/chrome/browser/chro...
File chrome/browser/chromeos/gdata/drive_api_operations.h (right):

https://chromiumcodereview.appspot.com/10836125/diff/2001/chrome/browser/chro...
chrome/browser/chromeos/gdata/drive_api_operations.h:55:
GetChangelistOperation(GDataOperationRegistry* registry,
Please add a comment about the role of |start_changestamp|

https://chromiumcodereview.appspot.com/10836125/diff/2001/chrome/browser/chro...
chrome/browser/chromeos/gdata/drive_api_operations.h:62: void SetURL(const GURL&
url);
Do we need this method?
Can't |url| be passed to the ctor?

[kochi, 2012-08-07 07:46:04]

https://chromiumcodereview.appspot.com/10836125/diff/2001/chrome/browser/chro...
File chrome/browser/chromeos/gdata/drive_api_operations.h (right):

https://chromiumcodereview.appspot.com/10836125/diff/2001/chrome/browser/chro...
chrome/browser/chromeos/gdata/drive_api_operations.h:55:
GetChangelistOperation(GDataOperationRegistry* registry,
On 2012/08/07 07:36:57, hashimoto wrote:
> Please add a comment about the role of |start_changestamp|

Done.

https://chromiumcodereview.appspot.com/10836125/diff/2001/chrome/browser/chro...
chrome/browser/chromeos/gdata/drive_api_operations.h:62: void SetURL(const GURL&
url);
Changed the comment to be more specific.

The knowledge of what URL should be used is centralized in
drive_api_operations.cc, and the users can be ignorant about
this.  The use case for this method is that if the
changelist is too big to fit in one response, it returns
the next page URL with a token.  Then the user can pass
that URL for the next page.

If we made |url| as a ctor parameter, the user would have to
know the first request URL.

[hashimoto, 2012-08-07 07:57:43]

https://chromiumcodereview.appspot.com/10836125/diff/2001/chrome/browser/chro...
File chrome/browser/chromeos/gdata/drive_api_operations.h (right):

https://chromiumcodereview.appspot.com/10836125/diff/2001/chrome/browser/chro...
chrome/browser/chromeos/gdata/drive_api_operations.h:62: void SetURL(const GURL&
url);
On 2012/08/07 07:46:04, Takayoshi Kochi wrote:
> Changed the comment to be more specific.
> 
> The knowledge of what URL should be used is centralized in
> drive_api_operations.cc, and the users can be ignorant about
> this.  The use case for this method is that if the
> changelist is too big to fit in one response, it returns
> the next page URL with a token.  Then the user can pass
> that URL for the next page.
> 
> If we made |url| as a ctor parameter, the user would have to
> know the first request URL.

What I meant was deleting SetURL and allowing passing empty GURL for the ctor
like DocumentsService::GetChangelist.
I thought allowing passing empty GURL for the ctor is better than exposing a
setter as public.
What do you think?

[kochi, 2012-08-07 09:06:52]

https://chromiumcodereview.appspot.com/10836125/diff/2001/chrome/browser/chro...
File chrome/browser/chromeos/gdata/drive_api_operations.h (right):

https://chromiumcodereview.appspot.com/10836125/diff/2001/chrome/browser/chro...
chrome/browser/chromeos/gdata/drive_api_operations.h:62: void SetURL(const GURL&
url);
Agreed, removed SetURL() from this file and
gdata_operations.cc.

[hashimoto, 2012-08-07 09:17:36]

lgtm