Bring in the latest pub

Fixes https://github.com/dart-lang/pub/issues/1914

Includes fixes for snappshotting and running executables in Dart 2 mode.

Change-Id: If35c22859b3985fee769e15d2606f484746f2926
Reviewed-on: https://dart-review.googlesource.com/58804
Commit-Queue: Nate Bosch <nbosch@google.com>
Reviewed-by: Kevin Moore <kevmoo@google.com>
diff --git a/CHANGELOG.md b/CHANGELOG.md
index c8b2546..2d201bc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,6 +16,8 @@
 
 #### Pub
 
+* Fix support for running executables in Dart 2 mode.
+
 #### Other Tools
 
 ## 2.0.0-dev.60.0
diff --git a/DEPS b/DEPS
index 76e7739..5682e70 100644
--- a/DEPS
+++ b/DEPS
@@ -110,7 +110,7 @@
   "ply_rev": "604b32590ffad5cbb82e4afef1d305512d06ae93",
   "pool_tag": "1.3.4",
   "protobuf_tag": "0.7.1",
-  "pub_rev": "7bdcf4e4de85a7a8c7a322511b8198f1b6cb0a73",
+  "pub_rev": "d84173eeb03c328ed533469108ce81b11d736a80",
   "pub_semver_tag": "1.4.1",
   "quiver_tag": "5aaa3f58c48608af5b027444d561270b53f15dbf",
   "resource_rev":"af5a5bf65511943398146cf146e466e5f0b95cb9",