Roll chromium_revision a8b75a6..1f9589b (357542:357797)

Change log: https://chromium.googlesource.com/chromium/src/+log/a8b75a6..1f9589b
Full diff: https://chromium.googlesource.com/chromium/src/+/a8b75a6..1f9589b

Changed dependencies:
* src/tools/gyp: https://chromium.googlesource.com/external/gyp.git/+log/3f21260..2c1e6cc
DEPS diff: https://chromium.googlesource.com/chromium/src/+/a8b75a6..1f9589b/DEPS

No update to Clang.

TBR=
CQ_EXTRA_TRYBOTS=tryserver.webrtc:win_baremetal,mac_baremetal,linux_baremetal

Review URL: https://codereview.webrtc.org/1431743003

Cr-Commit-Position: refs/heads/master@{#10505}
diff --git a/DEPS b/DEPS
index b333794..7d3ef31 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': 'a8b75a6d21f35fc1b99578036114a998b50fc760',
+  'chromium_revision': '1f9589b284dc7f7091eaaaa1cab0cc3cc7a3efe7',
 }
 
 # NOTE: Prefer revision numbers to tags for svn deps. Use http rather than