[Sync] Ensure failed datatypes handler preserves error location.
[Sync] Ensure failed datatypes handler preserves error location.

BUG=105139
TEST=trigger an error during model association, inspect about:sync to ensure
line numbers are displayed in error message.


Review URL: http://codereview.chromium.org/8637023

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@112375 0039d316-1c4b-4281-b951-d872f2087c98

adobe/chromium,yitian134/chromium,adobe/chromium,adobe/chromium,gavinp/chromium,yitian134/chromium,gavinp/chromium,ropik/chromium,yitian134/chromium,gavinp/chromium,ropik/chromium,ropik/chromium,adobe/chromium,adobe/chromium,yitian134/chromium,adobe/chromium,yitian134/chromium,gavinp/chromium,yitian134/chromium,gavinp/chromium,gavinp/chromium,adobe/chromium,yitian134/chromium,yitian134/chromium,adobe/chromium,ropik/chromium,yitian134/chromium,ropik/chromium,ropik/chromium,yitian134/chromium,adobe/chromium,ropik/chromium,gavinp/chromium,ropik/chromium,adobe/chromium,gavinp/chromium,adobe/chromium,ropik/chromium,gavinp/chromium,gavinp/chromium