Bring in the latest pub.

Once this lands, I intend to merge it into dev.

R=jmesserly@google.com

Review URL: https://codereview.chromium.org/1880413003 .
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5497a37..af5ee69 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -33,6 +33,10 @@
   * Both `pub get` and `pub upgrade` now have a `--no-precompile` flag that
     disables precompilation of executables and transformed dependencies.
 
+  * `pub publish` now resolves symlinks when publishing from a Git repository.
+    This matches the behavior it always had when publishing a package that
+    wasn't in a Git repository.
+
 * Dart Dev Compiler
   * The **experimental** `dartdevc` executable has been added to the SDK.
 
diff --git a/DEPS b/DEPS
index 9ae0509..c64cf6d 100644
--- a/DEPS
+++ b/DEPS
@@ -72,7 +72,7 @@
   "plugin_tag": "@0.1.0",
   "pool_tag": "@1.2.1",
   "protobuf_tag": "@0.5.0+1",
-  "pub_rev": "@c1405b945c6d818c8cfe78334e8d4b11fd913103",
+  "pub_rev": "@5257a0630a8db4f1ae339910eef5080ce384afc7",
   "pub_cache_tag": "@v0.1.0",
   "pub_semver_tag": "@1.2.1",
   "quiver_tag": "@0.21.4",