Version 2.19.0-255.2.beta

* Cherry-pick 003ea967a56e0dd0e2744099c78a46fa5ddc6c57 to beta
diff --git a/DEPS b/DEPS
index d6be5ed..af6f582 100644
--- a/DEPS
+++ b/DEPS
@@ -112,7 +112,7 @@
   "dart_style_rev": "49bc3ff32b5578b6e19f8fd376d668130941ee29", # manually rev'd
 
   "dartdoc_rev": "691fa9640aaeda2044627ae8d7e072572344e499",
-  "devtools_rev": "40aae5e5ea2118e2b6dee8a8a20f166f7cec4270",
+  "devtools_rev": "b21cd59f1f6bb60cacd59ba39e376d2a50d82f74",
   "ffi_rev": "fb5f2667826c0900e551d19101052f84e35f41bf",
   "file_rev": "b2e31cb6ef40b223701dbfa0b907fe58468484d7",
   "fixnum_rev": "e0b17cc1f639c55a9c24947392c64b5a68992535",
diff --git a/tools/VERSION b/tools/VERSION
index 9047c02..2ccad33 100644
--- a/tools/VERSION
+++ b/tools/VERSION
@@ -28,4 +28,4 @@
 MINOR 19
 PATCH 0
 PRERELEASE 255
-PRERELEASE_PATCH 1
+PRERELEASE_PATCH 2