Incrementing VERSION to 53.0.2785.15

Cr-Commit-Position: refs/branch-heads/2785@{#99}
Cr-Branched-From: 68623971be0cfc492a2cb0427d7f478e7b214c24-refs/heads/master@{#403382}
diff --git a/chrome/VERSION b/chrome/VERSION
index 3a0e252..0ca51648 100644
--- a/chrome/VERSION
+++ b/chrome/VERSION
@@ -1,4 +1,4 @@
 MAJOR=53
 MINOR=0
 BUILD=2785
-PATCH=14
+PATCH=15