Roll chromium_revision 4918765..3b8be21 (363393:363445)

Change log: https://chromium.googlesource.com/chromium/src/+log/4918765..3b8be21
Full diff: https://chromium.googlesource.com/chromium/src/+/4918765..3b8be21

No dependencies changed.
No update to Clang.

TBR=
NOTRY=True

Review URL: https://codereview.webrtc.org/1503973002

Cr-Commit-Position: refs/heads/master@{#10916}
diff --git a/DEPS b/DEPS
index 123868a..d76d870 100644
--- a/DEPS
+++ b/DEPS
@@ -6,7 +6,7 @@
 vars = {
   'extra_gyp_flag': '-Dextra_gyp_flag=0',
   'chromium_git': 'https://chromium.googlesource.com',
-  'chromium_revision': '491876565010e0d7d4a036460188a66c2b34c946',
+  'chromium_revision': '3b8be2124e3f1d3ce09d534315fb9a8f50ead086',
 }
 
 # NOTE: Prefer revision numbers to tags for svn deps. Use http rather than