Update DEPS for https://codereview.chromium.org/1369743003

BUG=

Review URL: https://codereview.chromium.org//1370813003 .

Author: alan-knight

tools/deps/dartium.deps/DEPS

@@ -14,7 +14,7 @@ vars.update({
   "dartium_chromium_commit": "62a7524d4f71c9e0858d24b0aa1bbff3a2d09bff",
   "chromium_base_revision": "297060",
   "dartium_webkit_branch": "/blink/branches/dart/dartium",
-  "dartium_webkit_revision": "202670",
+  "dartium_webkit_revision": "202671",
 
   # We use mirrors of all github repos to guarantee reproducibility and
   # consistency between what users see and what the bots see.