Update to git-1.9.0.

Update to git-1.9.0.

Also, allow multiple git installations to exist side-by-side.
This makes it easier to revert back to an old version quickly.

BUG=
R=maruel@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=258058

[M-A Ruel, 2014-03-19 00:52:40]

lgtm

[mmoss, 2014-03-19 05:11:15]

https://codereview.chromium.org/203463004/diff/40001/bootstrap/win/win_tools.bat
File bootstrap/win/win_tools.bat (right):

https://codereview.chromium.org/203463004/diff/40001/bootstrap/win/win_tools....
bootstrap/win/win_tools.bat:67: if "%DEPOT_TOOLS_GIT_190%" == "0" goto
:GIT_1852_CHECK
I don't remember, do win vars == "0" if they are unset? If not, maybe this
should be != "1".

https://codereview.chromium.org/203463004/diff/40001/bootstrap/win/win_tools....
bootstrap/win/win_tools.bat:133: call "%WIN_TOOLS_ROOT_DIR%\git.bat" config
--global core.autocrlf false
Make these --system, to it modifies the config we ship in the git package,
rather than the user's config. Unless you're still planning to get rid of them
altogether, like we were talking about before.

https://codereview.chromium.org/203463004/diff/40001/update_depot_tools.bat
File update_depot_tools.bat (right):

https://codereview.chromium.org/203463004/diff/40001/update_depot_tools.bat#n...
update_depot_tools.bat:24: :: Will download svn and python.
and git.

[szager1, 2014-03-19 05:41:57]

https://codereview.chromium.org/203463004/diff/40001/bootstrap/win/win_tools.bat
File bootstrap/win/win_tools.bat (right):

https://codereview.chromium.org/203463004/diff/40001/bootstrap/win/win_tools....
bootstrap/win/win_tools.bat:67: if "%DEPOT_TOOLS_GIT_190%" == "0" goto
:GIT_1852_CHECK
On 2014/03/19 05:11:15, mmoss wrote:
> I don't remember, do win vars == "0" if they are unset? If not, maybe this
> should be != "1".

I tested this; it only evaluates true if the var is set to a literal "0".

https://codereview.chromium.org/203463004/diff/40001/bootstrap/win/win_tools....
bootstrap/win/win_tools.bat:133: call "%WIN_TOOLS_ROOT_DIR%\git.bat" config
--global core.autocrlf false
On 2014/03/19 05:11:15, mmoss wrote:
> Make these --system, to it modifies the config we ship in the git package,
> rather than the user's config. Unless you're still planning to get rid of them
> altogether, like we were talking about before.

Done.

https://codereview.chromium.org/203463004/diff/40001/update_depot_tools.bat
File update_depot_tools.bat (right):

https://codereview.chromium.org/203463004/diff/40001/update_depot_tools.bat#n...
update_depot_tools.bat:24: :: Will download svn and python.
On 2014/03/19 05:11:15, mmoss wrote:
> and git.

Done.

[mmoss, 2014-03-19 14:17:11]

https://codereview.chromium.org/203463004/diff/40001/bootstrap/win/win_tools.bat
File bootstrap/win/win_tools.bat (right):

https://codereview.chromium.org/203463004/diff/40001/bootstrap/win/win_tools....
bootstrap/win/win_tools.bat:67: if "%DEPOT_TOOLS_GIT_190%" == "0" goto
:GIT_1852_CHECK
On 2014/03/19 05:41:57, szager1 wrote:
> On 2014/03/19 05:11:15, mmoss wrote:
> > I don't remember, do win vars == "0" if they are unset? If not, maybe this
> > should be != "1".
> 
> I tested this; it only evaluates true if the var is set to a literal "0".

OK, I guess I just misunderstood the intent. I thought you were saying "if 190
isn't set, try 1852; if 1852 isn't set, try 180", but it's really "use 190
unless it's explicitly disabled, then use 1852, unless 1852 is explicitly
disabled, then use 180". I guess that's OK, but as more versions are supported,
it gets more tedious to enable an older version, because you have to explicitly
disable all the more recent ones (and by implication, be aware they've been
added and what the proper invocation is for disabling them).

Maybe the most recent one can always be "use unless disabled" but all the older
ones can be "don't use unless enabled", with a fallthrough to "oops, you forgot
to enable at least one version of git".

[szager1, 2014-03-19 19:22:10]

Committed patchset #4 manually as r258058 (presubmit successful).

[szager1, 2014-03-19 19:22:41]

On 2014/03/19 14:17:11, mmoss wrote:
>
https://codereview.chromium.org/203463004/diff/40001/bootstrap/win/win_tools.bat
> File bootstrap/win/win_tools.bat (right):
> 
>
https://codereview.chromium.org/203463004/diff/40001/bootstrap/win/win_tools....
> bootstrap/win/win_tools.bat:67: if "%DEPOT_TOOLS_GIT_190%" == "0" goto
> :GIT_1852_CHECK
> On 2014/03/19 05:41:57, szager1 wrote:
> > On 2014/03/19 05:11:15, mmoss wrote:
> > > I don't remember, do win vars == "0" if they are unset? If not, maybe this
> > > should be != "1".
> > 
> > I tested this; it only evaluates true if the var is set to a literal "0".
> 
> OK, I guess I just misunderstood the intent. I thought you were saying "if 190
> isn't set, try 1852; if 1852 isn't set, try 180", but it's really "use 190
> unless it's explicitly disabled, then use 1852, unless 1852 is explicitly
> disabled, then use 180". I guess that's OK, but as more versions are
supported,
> it gets more tedious to enable an older version, because you have to
explicitly
> disable all the more recent ones (and by implication, be aware they've been
> added and what the proper invocation is for disabling them).
> 
> Maybe the most recent one can always be "use unless disabled" but all the
older
> ones can be "don't use unless enabled", with a fallthrough to "oops, you
forgot
> to enable at least one version of git".

That sounds like a good follow-up change :)