Roll chromium_revision 271c6cc..3dd2edf (309333:310717)

Relevant changes:
* src/buildtools: 23a4e2f..451dcd0
* src/third_party/boringssl/src: 306e520..aac2f6a
* src/third_party/openmax_dl: 0164270..1a4171c
* src/tools/gyp: fe00999..82b0804
* src/tools/swarming_client: 119b084..c44f572
Details: https://chromium.googlesource.com/chromium/src/+/271c6cc..3dd2edf/DEPS

Clang version was not updated in this roll.

R=pbos@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/34709004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@8047 4adac7df-926f-26a2-2b94-8c16560cd09d