gdata: Remove logic to detect incompatibility proto

gdata: Remove logic to detect incompatibility proto

The logic is no longer needed as we've been relying on the version number
since crrev.com/147782. Along the way, remove tests for the logic, and
make GDataEntry/GDataFile/GDataDirectory::FromProto() return void.

It's a bit sad to see gdata_files_unittest.cc gone, but gdata_files.h/cc
will also be removed in the near future anyway.

BUG=141135
TEST=file manager works as before
TBR=thakis@chromium.org
for chrome_tests.gypi

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=152175

[satorux1, 2012-08-17 22:19:42]

sorry for not doing this earlier.

[achuithb, 2012-08-17 22:24:54]

Nice bit of cleanup!

lgtm++

http://codereview.chromium.org/10857063/diff/1/chrome/browser/chromeos/gdata/...
File chrome/browser/chromeos/gdata/gdata_files.h (right):

http://codereview.chromium.org/10857063/diff/1/chrome/browser/chromeos/gdata/...
chrome/browser/chromeos/gdata/gdata_files.h:67: // TODO(achuith,satorux): Should
this be virtual?
I meant to ask you, should ToProto be virtual? I think it should be.

[satorux1, 2012-08-17 22:28:31]

http://codereview.chromium.org/10857063/diff/1/chrome/browser/chromeos/gdata/...
File chrome/browser/chromeos/gdata/gdata_files.h (right):

http://codereview.chromium.org/10857063/diff/1/chrome/browser/chromeos/gdata/...
chrome/browser/chromeos/gdata/gdata_files.h:67: // TODO(achuith,satorux): Should
this be virtual?
On 2012/08/17 22:24:55, achuith.bhandarkar wrote:
> I meant to ask you, should ToProto be virtual? I think it should be.

probably, but I guess it doesn't have to be as the code is working, and the code
will be gone not in the distant future anyway.