drive: Introduce kInitialChangestamp to DriveResourceMetadataTest

drive: Introduce kInitialChangestamp to DriveResourceMetadataTest

This is in preparation for adding tests that check the per-directory
changestamp to be zero, for newly added directories by RefreshDirectory().
In other words, we need to distinguish zero from the initial changestamp.

BUG=178348
TEST=none

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=187505

[hashimoto, 2013-03-12 05:07:54]

lgtm with a nit

https://codereview.chromium.org/12706005/diff/1/chrome/browser/chromeos/drive...
File chrome/browser/chromeos/drive/drive_resource_metadata_unittest.cc (right):

https://codereview.chromium.org/12706005/diff/1/chrome/browser/chromeos/drive...
chrome/browser/chromeos/drive/drive_resource_metadata_unittest.cc:35: const
int64 kInitialChangestamp = 100;
"initial" seems a bit confusing, it sounds like something similar to "default".
(i.e. 0 for integer values)
How about using another term like "example" or "test"?

[satorux1, 2013-03-12 05:12:00]

https://codereview.chromium.org/12706005/diff/1/chrome/browser/chromeos/drive...
File chrome/browser/chromeos/drive/drive_resource_metadata_unittest.cc (right):

https://codereview.chromium.org/12706005/diff/1/chrome/browser/chromeos/drive...
chrome/browser/chromeos/drive/drive_resource_metadata_unittest.cc:35: const
int64 kInitialChangestamp = 100;
On 2013/03/12 05:07:54, hashimoto wrote:
> "initial" seems a bit confusing, it sounds like something similar to
"default".
> (i.e. 0 for integer values)
> How about using another term like "example" or "test"?

Sounds reasonable. Changed it to kTestChangestamp.

[hashimoto, 2013-03-12 05:17:51]

lgtm 
Please update change description before commit

[satorux1, 2013-03-12 05:18:38]

Committed patchset #2 manually as r187505 (presubmit successful).

[satorux1, 2013-03-12 05:19:07]

oops. sorry, too late. shouldn't be a big issue...