Fix mouse over renderer crash with URLs over 2MB in size.
Fix mouse over renderer crash with URLs over 2MB in size.

BUG=102287
TEST=Mouse over the link in test.html from bug report. It should not crash the renderer.

Review URL: http://codereview.chromium.org/8417057

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@108668 0039d316-1c4b-4281-b951-d872f2087c98

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