Handle updating depot_tools repos that are git cloned.

update_depot_tools.bat

Index: update_depot_tools.bat
diff --git a/update_depot_tools.bat b/update_depot_tools.bat
index 990ea31eea56668ce52e6d7864bd5e7df8eb3fba..0b12cd1a6ad81684c90e8e17190dafb7bfd2741c 100644
--- a/update_depot_tools.bat
+++ b/update_depot_tools.bat
@@ -31,5 +31,13 @@ goto :EOF
 
 :GIT_UPDATE
 cd /d "%~dp0."
+call git config remote.origin.fetch > NUL

[M-A Ruel, 2012/04/29 00:49:08]

I prefer to do the reverse order of the check. First check for git svn, then
check for a remote.

The reason is that I git svn clone, then git clone this svn clone and also setup
git svn on it. So I end up with one (or 2) git remotes and one git-svn remote.

As such, I want the git svn remote to have higher priority.

[cmp, 2012/04/29 00:57:03]

I asked M-A over IM if he would explain why he wouldn't just switch to use the
supported Git repo for depot_tools after this change lands, to which he replied
"ok."  So the current patchset is still the preferred way to go.

Before this would land, I'll send a PSA to users on chromium-dev@ letting them
know that they should switch any Git-based copy of depot_tools to use the new
supported repo.

+if errorlevel 1 goto :GIT_SVN_UPDATE
+call git fetch -q origin
+call git rebase -q origin
+goto :EOF
+
+:GIT_SVN_UPDATE
+cd /d "%~dp0."
 call git svn rebase -q -q
 goto :EOF