Don't eat newlines in CL descriptions when merging changes using drover.

BUG=80589
TEST=Merge a CL using drover and when prompted to upload, check that the original CL description still has its linebreaks.
Review URL: http://codereview.chromium.org/6893095

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@83561 0039d316-1c4b-4281-b951-d872f2087c98

drover.py

@@ -118,10 +118,10 @@ def inCheckoutRoot(path):
 def getRevisionLog(url, revision):
   """Takes an svn url and gets the associated revision."""
   svn_log = subprocess2.check_output(
-      ['svn', 'log', url, '-r', str(revision)]).splitlines()
-  # Don't include the header lines and the trailing "---..." line and eliminate
-  # any '\r's.
-  return ''.join([l.replace('\r','') for l in svn_log[3:-1]])
+      ['svn', 'log', url, '-r', str(revision)],
+      universal_newlines=True).splitlines(True)
+  # Don't include the header lines and the trailing "---..." line.
+  return ''.join(svn_log[3:-1])
 
 def getSVNVersionInfo():
   """Extract version information from SVN"""