roll chromium revision to head in attempt to resolve build time performance hit…

roll chromium revision to head in attempt to resolve build time performance hit due to external compilers on windows.
BUG=none
TESTED=untested
R=harryjin@google.com

Review URL: https://webrtc-codereview.appspot.com/49299004

git-svn-id: http://libyuv.googlecode.com/svn/trunk@1422 16f28f9a-4ce2-e073-06de-1de4eb20be90

DEPS

@@ -6,7 +6,7 @@ vars = {
 
   # Roll the Chromium Git hash to pick up newer versions of all the
   # dependencies and tools linked to in setup_links.py.
-  'chromium_revision': '31f54fb62bd9696392f1a767014a8abf5e33edf1',
+  'chromium_revision': '1a92b387b1b1488d468f65d856924dcf3e99a9af',
 }
 
 hooks = [