Roll closure compiler

Change log:
https://github.com/google/closure-compiler/compare/2f95290ea61dd4f1b5a3bf9d0fe3aa8e3244babf...c64418fd5518bb60aeb6a627d2bcc46a3d4be788
chrome_extensions.js: 754b5d249801020f5d71df9b7b576550f56972dc -> 462f6bc6508621ebeb7cf9a51fca7d069d2a7b85

R=dbeam@chromium.org
TBR=sergeyu

Review URL: https://codereview.chromium.org/2180623002 .

Cr-Commit-Position: refs/heads/master@{#407318}
5 files changed