First tab navigation may fail with TabCrashException

BUG=329271
TEST=manual
NOTRY=True

Review URL: https://codereview.chromium.org/103433004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242190 0039d316-1c4b-4281-b951-d872f2087c98
Disk cache: Fix overflow detection for sparse entries.

BUG=328231
TEST=none
R=cpu@chromium.org

Review URL: https://codereview.chromium.org/108583005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242191 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 242191